In a double-entry accounting system, which statement is true?

• A. One account affected
• B. Debits and credits must balance across at least two accounts.
• C. Assets must always increase
• D. Revenues are never affected by expenses.

Answer: (B)

Every transaction in double-entry accounting has a dual effect: debits and credits must be recorded for at least two accounts so total debits equal total credits. This balancing acts as a built-in check that keeps the accounting equation in balance (assets = liabilities + equity) and ensures that each economic event is fully reflected.

That makes the statement about balancing across at least two accounts the correct one. If you recorded only a single account, there would be no corresponding entry to keep the books in balance, which would misstate the financial position.

The other statements don't hold up. Assets don’t always increase—transactions can reduce assets (for example, paying cash or disposing of an asset). And revenues being never affected by expenses isn’t correct either, because expenses reduce net income and thereby affect overall equity; while they are separate, they interact within the financial results and the accounting equation.