What is the double-spending problem in blockchain?
a) When a miner solves two blocks at once
b) When the same digital currency is spent more than once
c) When a blockchain forks into two
d) When miners work together to solve a block
Answer:
b) When the same digital currency is spent more than once
Explanation:
The double-spending problem refers to the risk of a digital currency being spent more than once due to its electronic nature, which blockchain helps prevent through decentralized validation.