Resource use is allocatively efficient if the ( )
选项：

A:total cost of what the resource produces is less than the total
benefit of what is produced.
B:total cost of what the resource produces is equal to the total
benefit of what is produced.
C:marginal benefit of what the resource produces has diminished to
zero.
D:marginal cost of what the resource produces is equal to the marginal
benefit of what is produced.