A bank transfer must debit one account and credit another as ONE unit — either both happen or neither does, even on failure. Which ACID property guarantees this?
A.Atomicity — transactions are all-or-nothing
All-or-nothing = atomicity. Correct.
B.Consistency
Consistency is about valid states — not indivisibility.
C.Isolation
Isolation concerns concurrent visibility.
D.Durability
Durability concerns survival after commit.
Why this answer
ACID: Atomicity = all-or-nothing transaction unit; Consistency = moves between valid states; Isolation = concurrent transactions don't interfere; Durability = committed data survives crashes. 'Both or neither' is always atomicity.
Correct answer: A · Last reviewed 2026-11-05
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