7. Sue quit her high-pressure accounting job to open a store that sells sea shells by the sea shore. She earned $75,000 a year as an accountant. Now she pays herself only $15,000 a year. The implicit cost of Sue's time selling sea shells this year is

A) $75,000.

B) $60,000.

C) $15,000.

D) $90,000.

E) $50,000.