Lashondra is the owner/operator of an interior design firm. Last year she earned $400,000 in total revenue. Her explicit costs were $200,000 (assume that this amount represents the total opportunity cost of these resources). During the course of the year she received offers to work for other design firms. One offer would have paid her $120,000 per year and the other would have paid her $130,000 per year. Lashondra's economic profit is equal to:

-$50,000.

$70,000.

$200,000.

$0.