In economic analysis,the principle of marginal analysis refers to:

A) dividing large problems into smaller,more manageable ones.
B) the notion that a group's problems can be effectively analyzed by focusing on only a small subsample of the group.
C) the result that the optimal quantity of an activity is that at which marginal benefit is equal to marginal cost.
D) the result that the optimal quantity of an activity is that at which the net benefit of the representative,or marginal,individual is maximized.

Marginal analysis involves comparing the additional benefits and costs of a particular activity, and determining the optimal quantity of that activity by selecting the quantity at which marginal benefit equals marginal cost. This principle is based on the idea that a society or individual will continue to engage in an activity as long as the marginal benefit is greater than the marginal cost, but will stop when the marginal cost exceeds the marginal benefit. Therefore, the optimal level of activity is found at the point where marginal benefit equals marginal cost.