On August 31 of this year, Kinga sold land with a cost of $20,000 for $40,000. Kinga collected $10,000 this year and is scheduled to receive $7,500 each year for four years starting next year plus an acceptable rate of interest. Kinga's gain recognized next year is

A) $3,750.

B) $7,500.

C) $20,000.

D) $40,000.