Control Accounts in Sales Ledger Steps:

• Identify purpose of sales ledger control account: summarizes total balances for all credit customers.
• Identify purpose of individual sales ledger accounts: track transactions and balances for each customer separately.
• Compare functions: control account enables quick overview and error checking; individuals provide detailed records.
• Determine why both are needed: totals for efficiency, details for specific management and verification.

Why B is correct:

• Option B ("1 only") aligns with the primary reason being a summarized total (statement 1), as control accounts aggregate individual details per accounting standards.

Why the others are wrong:

• A includes extraneous reasons beyond core summarization.
• C omits the essential total balance function.
• D references undefined or incorrect statement 4.

Not enough information on statements 2, 3, 4 to fully evaluate.

Final answer: Not enough information.