Suppose a Firm with the Usual U- Shaped Cost Curves

Suppose a firm with the usual U- shaped cost curves is producing a level of output such that its short- run costs are as follows: ATC = $0.37 per unit AVC = $0.32 per unit AFC = $0.05 per unit MC = $0.43 per unit
Given these short- run costs,as the firm increases its output,which of the following statements is true?

A) Average product of the variable factor must be increasing.
B) Marginal product of the variable factor is at its minimum point.
C) Marginal product of the variable factor must be increasing.
D) Marginal product of the variable factor must be decreasing.
E) The point of diminishing average product of the variable factor has not yet been reached.