At the end of the current accounting period, account balances were as follows: Cash, $$29,000$; Accounts Receivable, $$43,000$; Common Stock, $$21,000$; Retained Earnings, $$12,000.$ Liabilities at the end of the period were:

A$.$ $$72,000.$

B$.$ $$39,000.$

C$.$ $$51,000.$

D$.$ $$60,000.$