[
  {
    "id": 1,
    "question": "What best describes a distributed system?",
    "options": {
      "A": "A system running on a single powerful computer",
      "B": "A collection of independent computers appearing as a single coherent system",
      "C": "A database replicated in multiple files",
      "D": "A centralized system with backup servers"
    }
  },
  {
    "id": 2,
    "question": "In distributed systems, asynchronous communication primarily enables:",
    "options": {
      "A": "Tight coupling",
      "B": "Immediate request-response",
      "C": "Direct memory access",
      "D": "Loose coupling"
    }
  },
  {
    "id": 3,
    "question": "A standard message queue is ideal for:",
    "options": {
      "A": "Broadcasting events to all services",
      "B": "Encrypting REST calls",
      "C": "Storing smart contracts",
      "D": "Work distribution (e.g., resizing images)"
    }
  },
  {
    "id": 4,
    "question": "In distributed systems, retries are generally considered:",
    "options": {
      "A": "Immediate",
      "B": "Impossible",
      "C": "Inevitable",
      "D": "Unnecessary"
    }
  },
  {
    "id": 5,
    "question": "A cryptocurrency wallet (running on our phone or computer) primarily stores:",
    "options": {
      "A": "Coins owned by the user",
      "B": "Blocks from the blockchain",
      "C": "Gas to sign transactions",
      "D": "Private (and public) keys"
    }
  },
  {
    "id": 6,
    "question": "The Bitcoin Lightning Network is designed to:",
    "options": {
      "A": "Replace Ethereum smart contracts",
      "B": "Equalize PoW energy consumption",
      "C": "Enable faster off-chain Bitcoin transactions",
      "D": "Change Bitcoin's supply cap"
    }
  },
  {
    "id": 7,
    "question": "RPC can cause problems if developers forget that:",
    "options": {
      "A": "It uses HTTP for communication",
      "B": "It requires JSON encoding",
      "C": "It needs a message broker to work",
      "D": "It is still a network call and can fail"
    }
  },
  {
    "id": 8,
    "question": "In Solidity, a mapping is most similar to:",
    "options": {
      "A": "An array with elements",
      "B": "A dictionary (key-value store)",
      "C": "A loop with fixed iterations",
      "D": "A function implementing a feature"
    }
  },
  {
    "id": 9,
    "question": "What is React?",
    "options": {
      "A": "A database management system",
      "B": "A free and open-source front-end JavaScript library",
      "C": "A backend framework for Node.js",
      "D": "A CSS styling library"
    }
  },
  {
    "id": 10,
    "question": "What is used to pass data from a parent component to a child component in React?",
    "options": {
      "A": "Props",
      "B": "State",
      "C": "Events",
      "D": "Hooks"
    }
  },
  {
    "id": 11,
    "question": "What is the main purpose of the Virtual DOM in React?",
    "options": {
      "A": "To store sensitive application data",
      "B": "To create a CRUD design for objects",
      "C": "To efficiently update the browser DOM by comparing changes",
      "D": "To replace JavaScript in modern browsers"
    }
  },
  {
    "id": 12,
    "question": "Why does React require a key attribute when rendering lists?",
    "options": {
      "A": "To uniquely identify items for efficient updates",
      "B": "To apply CSS styling for each element",
      "C": "To be able to present escaped HTML data",
      "D": "To enable linking to the list items"
    }
  }
]