Ginger bought a phone that came with a $10 rebate. Ginger should fill out and mail in the rebate form if:

A.the opportunity cost of the time and trouble of sending in the rebate form is less than $10.

B.the opportunity cost of the time and trouble of sending in the rebate form is more than $10.

C.Ginger’s surplus from purchasing the phone was less than $10.

D.she would have bought the phone without the rebate, and so sending in the rebate form involves no opportunity cost.

正确答案：the opportunity cost of the time and trouble of sending in the rebate form is less than $10.