Which of the following describes ACID properties in databases?

• A. Atomicity, Consistency, Isolation, Durability
• B. Availability, Consistency, Integrity, Durability
• C. Atomicity, Concurrency, Isolation, Durability
• D. Access, Consistency, Isolation, Durability

Answer: (A)

ACID properties describe how a database guarantees reliable, correct processing of transactions. Atomicity means a transaction is all-or-nothing: either every operation in the transaction succeeds, or none do, with a rollback if anything fails. Consistency ensures that the database transforms from one valid state to another, preserving all integrity constraints and rules. Isolation ensures that concurrent transactions don't interfere with each other or expose intermediate states, preventing anomalies like reading partial results. Durability means that once a transaction is committed, its effects are permanent even in the event of a crash, thanks to durable storage and proper logging.

Other terms in the options come from different ideas: Availability is about being accessible and responsive, not guaranteeing transactional behavior; Integrity is a general idea of correctness but not one of the formal ACID properties; Concurrency and Access aren’t the standard ACID components. So the description that names Atomicity, Consistency, Isolation, and Durability best captures the intended guarantees for reliable transactions.