Answer:
C) is equal to 1.
Explanation:
The opportunity cost of growing a bushel of corn instead of cotton = cotton bushels / corn bushels
The opportunity cost of growing a bushel of cotton instead of corn = corn bushels / cotton bushels
if we multiply both opportunity costs, the answer will always be 1 = (cotton bushels / corn bushels) x (corn bushels / cotton bushels).
i.e. a/b x b/a = 1 always