the right answer is there just want to know why its right and why its wrong. thank you so much

Question 19 O out of 2.5 points The matching principle requires companies to record expenses Selected Answer Answers b. When they are incurred and paid a. When they are paid, whether or not they have been incurred. b. When they are incurred and paid. c On the first day of every accounting period, d. In the period they are incurred whether or not cash is paid. Question 20 O out of 2.5 points Which of the following accounts will have a zero-dollar balance after closing entries have been journalized and posted? Selected Answer Answers b. Unearnod Revenue a Service Revenue b. Unearned Revenue c. Supplies d. Accounts Payable The closing entries consists of closing Selected Answer: a. All asset and liability accounts. Answers: a. All asset and liability accounts. b. All permanent accounts. c. The Retained Earning account. d. All temporary accounts. The unadjusted trial balance for King Enterprises includes a $15,400 debit balance in supplies. At the end of the period, the balance of the supplies account totaled $13,200. The adjusting entry to record supplies expense would include which of the following? Selected Answer Answers c. $2,200 debit to supplies a. $2,200 credit to supplies b. $13,200 credit to supplies c. $2,200 debit to supplies d. $13,200 debit to supplies