Over the Range of Diminishing Marginal Product, If the Variable

Over the range of diminishing marginal product, if the variable input to a firm is increased:

A) output will increase more than in proportion to the increase in the input.
B) output will increase less than in proportion to the increase in the input.
C) output will increase exactly in proportion to the increase in the input.
D) output will increase more than in proportion to the increase in the inputs at first, but it will eventually increase less than in proportion to the increase in the input.
E) According to the principle of diminishing marginal product nothing will happen to output when only the variable input is increased.