Donald Trump operates a real estate business which uses the accrual method of accounting and a calendar year accounting period for federal income tax purposes. His niece, Mary, is a psychologist who operates a cash-method, calendar-year psychology business. During November, 2020, Mary provided psychological assessment services to Donalds business, and gave Donald a $10,000 bill for her services. Donalds business accrued the $10,000 expense in November, 2020, and paid $6,000 of the expense on December 15, 2020, and the remaining $4,000 on February 15, 2021. How much of the $10,000 expense can Donalds business deduct on its 2020 federal income tax return? Answer