Use the Following Figure to Answer the Questions

Multiple Choice

Use the following figure to answer the questions :
Figure 7-2 shows the total product curve for different levels of a variable input,labor.
-Let point A be the inflection point.When the quantity of labor employed is between A and D in Figure 7-2:

A) marginal product is negative.
B) marginal product is decreasing.
C) average product is increasing.
D) marginal product is increasing at a decreasing rate.