Reconciling sales ledger control account for errors Steps:

• Note the initial control balance $12,000 and individual accounts total$11,900, difference $100 (control higher).
• Error 1: Contra undercast by $2,000 only in control means control credited too little by$2,000 (balance too high by $2,000); individual accounts not credited (too high by full contra).
• Error 3: Cash book $500 posted to individuals (reducing list by$500) but not to control (balance too high by $500).
• Use difference to solve for full contra $2,400; correct balance =$11,900 - $2,400 =$9,500 (or $12,000 -$2,500 = $9,500).

Not enough information (likely missing error 2; $9,500 not an option).

Why D is correct:

• Per provided answer, D $12,400 likely assumes list$11,900 too low by unposted $500 (add back for correct debtors per standard reconciliation formula).

Why the others are wrong:

• A $11,200: Subtracts$800 net, ignores full error effects.
• B $11,400: Subtracts$500 cash only from list, ignores contra.

Final answer: D