plz explain the correct answer

29. The trial balance shows the following selected amounts and balances at the end of the fiscal year dated December 31, 2016. All accounts have their normal balances. Cash $10,400 Retained Earnings (1/1/16) $15,000 Salaries Payable $2,100 Insurance Expense $1,500 Accounts Receivable $17,300 Unearned Rent Revenue $3,600 Dividends $5,000 Office Supplies $5,700 Notes Payable $4,000 Repair Expense $14,000 Office Supplies Exp. $1,600 Service Revenue $34,700 Rent Revenue $11,900 Prepaid Insurance $2,500 Accounts Payable $6,800 Salaries Expense $18,100 Common Stock $4,000 What is the balance in Retained Earnings after journalizing and posting the closing entries? a. $26,400 b. $15,000 c. $25,000 d. $21,400 e. None of the above