Block chain refers to what type of technology?

• A. A centralized database controlled by a single entity.
• B. A method for encrypting data only.
• C. Distributed ledger technology.
• D. A cloud storage service.

Answer: (C)

Blockchain is a form of distributed ledger technology. It describes a shared, append-only ledger of transactions that is replicated across many computers (participants) in a network. Each new group of transactions becomes a block and is cryptographically linked to the previous block, creating an immutable chain. Because the ledger is maintained by a network rather than a single authority, no single entity controls it, which enhances transparency and resilience. Encryption helps secure data, but the defining feature is the distributed, tamper-evident ledger across multiple parties, not a centralized database, a standalone encryption method, or a cloud storage service.