Employees work during the month of December and earn $500. The paychecks will be issued\ to employees on January 3rd. What adjusting entry is required on December 31st?\ a. debit salary expense $500; credit salaries payable $500\ b. debit salaries payable $500; credit salary expense $500\ c. debit salaries receivable $500; credit salary expense $500\ d. debit salary expense $500; credit salaries receivable $500\ e. No adjusting entry is required because no cash has been paid.