[
  {
    "id": 1,
    "question": "Which system has a single point of failure?",
    "options": {
      "A": "Monolithic system",
      "B": "Peer-to-peer network",
      "C": "Distributed system",
      "D": "Content Delivery Network"
    }
  },
  {
    "id": 2,
    "question": "Vertical scaling is limited because:",
    "options": {
      "A": "Networks are unreliable",
      "B": "It depends on consensus",
      "C": "A single machine has a maximum capacity",
      "D": "It requires multiple data centers"
    }
  },
  {
    "id": 3,
    "question": "Replication helps with:",
    "options": {
      "A": "Increasing latency",
      "B": "Fault tolerance",
      "C": "Reducing decentralization",
      "D": "Removing consensus"
    }
  },
  {
    "id": 4,
    "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": 5,
    "question": "A producer in a messaging queue:",
    "options": {
      "A": "Processes messages",
      "B": "Stores blockchain blocks",
      "C": "Sends messages to a broker",
      "D": "Subscribes to topics"
    }
  },
  {
    "id": 6,
    "question": "REST is:",
    "options": {
      "A": "A binary serialization format",
      "B": "An architectural style using HTTP methods on resources",
      "C": "A consensus mechanism",
      "D": "A blockchain protocol"
    }
  },
  {
    "id": 7,
    "question": "In Ethereum, if two conflicting transactions attempt a double spend:",
    "options": {
      "A": "Both are accepted",
      "B": "Neither is accepted",
      "C": "A globally accepted order is selected and one is rejected",
      "D": "The sender asynchronously chooses which one wins"
    }
  },
  {
    "id": 8,
    "question": "Which of the following is required to retrieve (read) the Ether balance of a publicly known Ethereum address?",
    "options": {
      "A": "The private key",
      "B": "The mnemonics for the wallet account",
      "C": "Both the private key and the mnemonics",
      "D": "None of the above"
    }
  },
  {
    "id": 9,
    "question": "Ethereum is Proof of Stake. It prioritizes validators based on blockchain rules and:",
    "options": {
      "A": "CPU power",
      "B": "Network latency",
      "C": "Geographic location",
      "D": "Amount of cryptocurrency staked"
    }
  },
  {
    "id": 10,
    "question": "Solidity is primarily used to:",
    "options": {
      "A": "Build REST APIs",
      "B": "Develop operating systems",
      "C": "Mine Bitcoin",
      "D": "Write smart contracts for Ethereum"
    }
  },
  {
    "id": 11,
    "question": "If gas runs out during the execution of a transaction:",
    "options": {
      "A": "Execution stops and state changes from the current call revert",
      "B": "Only part of the smart contract storage updates",
      "C": "Changes to state are partially applied",
      "D": "Transaction becomes free"
    }
  },
  {
    "id": 12,
    "question": "Immutability in blockchain means:",
    "options": {
      "A": "The balance of an address cannot be updated in subsequent blocks",
      "B": "Data is deleted after one confirmation by a validator",
      "C": "Past blocks cannot be altered without changing subsequent blocks and gaining consensus",
      "D": "Other users cannot read transactions that don't belong to them"
    }
  }
]