Suppose That a Small Business Takes in Monthly Revenue of $100,000

Suppose that a small business takes in monthly revenue of $100,000. Labor, rental, energy, and other purchased input costs are $70,000. The owner/entrepreneur could earn $5,000 per month in another job, and the owner/entrepreneur could get a return of $5,000 each month if she sold her business and invested the net proceeds in a financial asset, such as a treasury bond. Which of the following correctly describes her monthly economic profit?

A) $90,000.
B) $80,000.
C) $25,000.
D) $20,000.