Prepare December 31 year-end adjusting journal entries, as needed, for the following items. a. b. C Depreciation on office equipment for the current year is $4,000. The Supplies account shows a balance of $1,900, but a count of supplies reveals only $600 on hand at year-end. Employees work Monday through Friday, and salaries of $2,500 per week are paid each Friday. The company's year-end falls on Thursday. d. Cash of $6,000 was collected on November 1 of the current year, for three months of services yet to be performed. Unearned Service Revenue was credited when the cash was received. e. f. The company initially records payments of all insurance premiums as Prepaid Insurance. The unadjusted trial balance at year-end shows a balance of $1,100 in Prepaid Insurance. A review of insurance policies reveals that $600 of insurance is unexpired. At year-end, the company received a utility bill for December's electricity usage of $450 that will be paid in early January.