The figure below shows Avery’s weekly production possibilities curve for scarves. For Avery, the opportunity cost of making a red scarf is:

The figure below shows Avery’s weekly production possibilities curve for scarves. For Avery, the opportunity cost of making a red scarf is:
A.decreasing.
B.1 blue scarf.
C.increasing.
D.zero.
正确答案：1 blue scarf.