試題詳解

1. Suppose the prices of a pair of jeans, a shirt, and a tie are $30, $20, and $10, respectively. Which of the following statements is true in this context?
(A)The opportunity cost of buying a pair of jeans is 2 ties.
(B)The opportunity cost of buying a tie is 3 pairs of jeans.
(C)The opportunity cost of buying a tie is 2 shirts.
(D)The opportunity cost of buying a shirt is 2 ties.