[
  {
    "id": 1,
    "question": "Which is true about distributed systems compared to monolithic systems?",
    "options": {
      "A": "They are more resilient but more complex",
      "B": "They always have a single point of failure",
      "C": "They cannot scale horizontally",
      "D": "They require downtime for maintenance"
    }
  },
  {
    "id": 2,
    "question": "RPC aims to:",
    "options": {
      "A": "Replace HTTP",
      "B": "Make remote calls look like local function calls",
      "C": "Store messages in queues",
      "D": "Encrypt all communication"
    }
  },
  {
    "id": 3,
    "question": "In Pub/Sub, if three services subscribe to a topic and one message is published:",
    "options": {
      "A": "All three receive a copy",
      "B": "Only one service receives it",
      "C": "Two services receive it",
      "D": "No one receives it until restart"
    }
  },
  {
    "id": 4,
    "question": "In Proof of Work, miners:",
    "options": {
      "A": "Stake coins",
      "B": "Create smart contracts",
      "C": "Vote on transactions",
      "D": "Solve complex mathematical puzzles"
    }
  },
  {
    "id": 5,
    "question": "A hot cryptocurrency wallet differs from a cold wallet because it:",
    "options": {
      "A": "Stores more coins",
      "B": "Is hardware-based",
      "C": "Is connected to the internet",
      "D": "Cannot send funds"
    }
  },
  {
    "id": 6,
    "question": "Exponential backoff means:",
    "options": {
      "A": "Retry at constant intervals",
      "B": "Stop retrying after one failure",
      "C": "Increase waiting time between retries",
      "D": "Retry immediately"
    }
  },
  {
    "id": 7,
    "question": "Which of the following is required to retrieve (read) the Ether balance of an Ethereum address?",
    "options": {
      "A": "A private key to sign the read request",
      "B": "Just the address",
      "C": "Both the private key and the address",
      "D": "None of the above"
    }
  },
  {
    "id": 8,
    "question": "What is used to pass data from a parent component to a child component in React?",
    "options": {
      "A": "State",
      "B": "Hooks",
      "C": "Events",
      "D": "Props"
    }
  },
  {
    "id": 9,
    "question": "What is the main purpose of the Virtual DOM in React?",
    "options": {
      "A": "To store application data permanently",
      "B": "To create a database for UI elements",
      "C": "To use TypeScript in browsers",
      "D": "To efficiently update the browser DOM by comparing changes"
    }
  },
  {
    "id": 10,
    "question": "What is sharding in distributed databases?",
    "options": {
      "A": "Data encryption",
      "B": "Splitting data across machines",
      "C": "Data duplication",
      "D": "Backup process"
    }
  },
  {
    "id": 11,
    "question": "In active-passive deployment, who handles write requests?",
    "options": {
      "A": "All nodes",
      "B": "Passive nodes",
      "C": "Active node",
      "D": "Paxos algorithm"
    }
  },
  {
    "id": 12,
    "question": "What does Two-Phase Commit ensure?",
    "options": {
      "A": "All-or-nothing transaction consistency",
      "B": "Data compression",
      "C": "Faster queries",
      "D": "Vertical scaling"
    }
  },
  {
    "id": 13,
    "question": "What is the key difference between fungible and non-fungible tokens?",
    "details": "Note: To answer the following questions, you might need to read the Lesson on Ethereum tokens (see Lesson tab).",
    "options": {
      "A": "Fungible tokens are faster to transfer",
      "B": "Non-fungible tokens are always more valuable",
      "C": "Non-fungible tokens only exist on Ethereum",
      "D": "Fungible tokens are interchangeable, non-fungible tokens are unique"
    }
  },
  {
    "id": 14,
    "question": "Where do ERC-20 tokens actually exist?",
    "options": {
      "A": "Inside smart contracts",
      "B": "In user wallets directly",
      "C": "In memory during a transaction",
      "D": "In mining pools"
    }
  },
  {
    "id": 15,
    "question": "How is fractional token ownership (e.g., 0.5 tokens) achieved in ERC-20?",
    "options": {
      "A": "By using floating-point numbers in Solidity",
      "B": "By storing larger integers and using decimals for display",
      "C": "By splitting tokens into separate contracts",
      "D": "By increasing gas fees"
    }
  },
  {
    "id": 16,
    "question": "Why are events like Transfer important in ERC-20?",
    "options": {
      "A": "They reduce gas costs",
      "B": "They store token balances",
      "C": "They allow external applications to track state changes",
      "D": "They replace smart contracts"
    }
  },
  {
    "id": 17,
    "question": "What is the benefit of using a library like OpenZeppelin?",
    "options": {
      "A": "It guarantees profits from tokens",
      "B": "It replaces the need for validators",
      "C": "It provides secure, reusable implementations of common standards",
      "D": "It removes the need for testing"
    }
  },
  {
    "id": 18,
    "question": "How do developers typically use OpenZeppelin contracts?",
    "options": {
      "A": "By copying code manually into their contracts",
      "B": "By importing them and using inheritance",
      "C": "By deploying them as standalone blockchains",
      "D": "By converting them into tokens"
    }
  }
]