The Marginal Units of Action Choice X

The marginal units of action choice X

A) Are the last ∆X units and tend to generate the greatest amount of marginal benefits
B) Are the last ∆X units and tend to generate the smallest amount of marginal costs
C) Are initial ∆X units, where ∆X represents the change in the units of X
D) Are the last ∆X units, where ∆X is the smallest amount you can add or subtract