Use the following to answer question 7:
Point Bread Tractor
A 20 0
B 18 1
C 14 2
D 8 3
E 0 4
Refer to the above schedule. Starting at point A, the opportunity cost of producing each successive unit of tractors is:
a constant 2 units of bread
8, 6, 4, and 2 units of bread
2, 4, 6, and 8 units of bread
D) the reciprocal of the output of tractors