Final answer:
The collection within the discount period requires recording a sales discount and debiting cash for the discounted amount. After the discount period, cash is debited for the full amount with no discount recorded.
Step-by-step explanation:
The correct entry to record the cash collection on the sale of merchandise on credit for $3,000, terms 1/10, n/30, depends on when the payment is made. If the collection is made within the discount period, the correct entry is option D: debit Cash for $2,970, credit Trade Receivables for $2,970, and debit Sales Discount for $30. If collected after the discount period, the correct entry is option C: debit Cash for $3,000 and credit Trade Receivables for $3,000, with no sales discount recorded.