Zelda is a recent fashion graduate. She started her own apparel store with an investment of $300,000. In the first year she made a profit of $60,000. If she had taken up a job as a fashion editor for a magazine, she would have earned $50,000 as salary per year. Also, she could have invested her capital, $300,000, in treasury bonds and earned an interest of $12,000. Thus, the amount $62,000 ($50,000 $12,000) would be Genevieve's
A) social cost.
B) break-even price.
C) reservation price.
D) opportunity cost.