Purpose of Sales Ledger Control Account Steps:

• Identify the sales ledger as the subsidiary ledger holding individual customer accounts.
• Recognize the control account as a summary in the general ledger mirroring sales ledger totals.
• Understand that differences between control and sales ledger totals signal errors.
• Prepare the control account to reconcile and pinpoint posting mistakes in individual accounts.

Why C is correct:

• Control accounts detect errors by comparing totals; discrepancies reveal incorrect postings in the sales ledger, per double-entry bookkeeping principles.

Why the others are wrong:

• A: Interest charging uses aging reports, not control accounts.
• B: Writing off debts relies on individual account reviews, not control totals.
• D: Prime entry books (e.g., sales day book) provide initial totals, not derived from control accounts.

Final answer: C