Required information [The following information applies to the questions displayed below.] Drs. Glenn Feltham and David Ambrose began operations of their physical therapy clinic, called Northland Physical Therapy, on January 1, 2020. The annual reporting period ends December 31. The trial balance on January 1, 2021, was as follows (the amounts are rounded to thousands of dollars to simplify): Account Titles Cash Debit $ 8 Credit Accounts Receivable 4 Supplies 4 Equipment 9 Accumulated Depreciation Software $ 2 5 2 Accumulated Amortization Accounts Payable Notes Payable (short-term) Salaries and Wages Payable Interest Payable Income Taxes Payable Deferred Revenue Common Stock Retained Earnings Service Revenue Depreciation Expense 5 0 14 7 Amortization Expense 0 Salaries and Wages Expense Supplies Expense 0 Interest Expense 0 Income Tax Expense 0 Totals $ 30 $ 30 Transactions during 2021 (summarized in thousands of dollars) follow: