first test B is wrong and previous question posted C was wrong. I am stuck.

In November 2017. Fred sold a boat for $20,000. There were no costs associated with the sale, and his adjusted basis at the time was $13,000. Fred received a $4.000 down payment, and the buyer agreed to make four additional payments of $4,000 each year, beginning in 2018. Fred reported a $7,000 gain in the year of sale. The buyer then made one $4.000 payment in 2018. but in 2020, Fred repossessed the boat because the buyer had not made any more payments. What is Fred's basis in the repossessed property? FRED : $7.000 $8,000 $12,000 $13,000