Insufficient data to determine correct inventory turnover Steps:

• Calculate recorded COGS: opening inventory $3600 + purchases$2800 - closing inventory $2400 =$4000.
• Gross profit = sales - COGS; correct gross profit is $1200, so correct COGS = sales -$1200.
• Average inventory requires correct opening and closing values; error likely in closing inventory, but amount unknown without sales or recorded gross profit.
• Inventory turnover = correct COGS / average inventory; cannot compute without sales to adjust for error.

Why the correct option is correct:

• Not applicable; no option fits due to missing sales figure needed to find error in records and correct COGS.

Why the others are wrong:

• A, B, C, D: All assume resolvable data, but sales or error magnitude absent, preventing accurate turnover calculation.

Final answer: Not enough information.