Published:   30-Nov--0001
(a) When a single entity or group of entities control more than 50% of the computing power on a blockchain network, giving them the ability to manipulate transactions
(b) A digital signature used to verify transactions
(c) A unique identifier for a transaction on the blockchain
(d) A public address for receiving cryptocurrency
Answer:
When a single entity or group of entities control more than 50% of the computing power on a blockchain network, giving them the ability to manipulate transactions