tina wants to be a rock 'n' roll singer. She cashed in all of her bank accounts that were paying her

4% interest. She took this $6,000 and spent it to produce a CD. Tina did not quit her day job at Abercrombie. After one year her CD sales had earned $2,400 in accounting profits. Tina's economic profits are

A.

$240.

B.

$2,640.

C.

$3,600.

D.

$2,160.