Deploy and Manage dApps BDC Practice Questions (Page 5)

Questions 21–25

1. 21expert · hard

   A dApp is being decommissioned. The team wants to preserve user funds and data while ensuring that the smart contract can no longer be used. Which sequence of actions is most appropriate?

   • ALeave the contract running but remove the frontend.
   • BTransfer all funds to the admin's address and then destroy the contract.
   • CDestroy the contract immediately and then publish a notice for users to contact support.
   • DFreeze the contract, allow users to withdraw funds, then destroy the contract after a notice period.
   Reveal Solution Discussion Select an answer first
2. 22application · medium

   A dApp's admin account is used to call privileged functions on a smart contract. The admin's private key is stored in a plaintext file on a shared development server. Which change is the most important to reduce the risk of unauthorized access?

   • AUse a multi-signature wallet for admin functions, but keep the private key in the same file.
   • BEncrypt the plaintext file with a password and keep it on the same server.
   • CChange the admin account's password on the server.
   • DMove the private key to a hardware security module (HSM) or a secure key management service.
   Reveal Solution Discussion Select an answer first
4. 23foundation · easy

   After deploying a smart contract using a development framework like Hardhat or Truffle, how can you verify its on-chain presence?

   • ABy reading the local project configuration file
   • BBy sending a test transaction to the contract's address
   • CBy checking the wallet balance of the deployer
   • DBy checking the transaction receipt and querying the contract address on a block explorer
   Reveal Solution Discussion Select an answer first
5. 24expert · hard

   A dApp's governance contract allows token holders to propose and vote on parameter changes. The team wants to prevent a malicious proposal from being executed immediately after it passes. Which mechanism should be added?

   • ARequire a higher quorum for all proposals.
   • BIncrease the voting period to 30 days.
   • CAllow the admin to veto any proposal after it passes.
   • DAdd a timelock contract that delays execution by a fixed period after a proposal passes.
   Reveal Solution Discussion Select an answer first
6. 25expert · hard

   A dApp has a governance token that allows holders to vote on protocol changes. The team wants to implement a time-lock for upgrades to give users time to review changes. What is the best way to implement this?

   • AUse a multi-sig wallet as the owner and require a majority vote before executing upgrades.
   • BUse a proxy pattern that allows upgrades only after a governance vote.
   • CImplement a timelock contract that delays the execution of upgrade transactions by a specified period.
   • DRequire a two-step upgrade process where the first step is a proposal and the second is execution.
   Reveal Solution Discussion Select an answer first