下列不属于谈话技巧的是（）。

A.善于激发下级的谈话愿望

B.善于启发下级讲真情实话

C.善于抓住重要问题

D.运用倾听技巧

E.直接批评下属

Which of the following conditions is most likely to exist for a typical production process when average product is at its maximum（）

A. Marginal product is increasing.

B. Marginal product is at a minimum.

C. Average variable cost is at a minimum.