For this case we have that the volume of the figure is composed of the volume of a prism and the volume of a pyramid:
The volume of the prism is given by:

Where:
: It is the area of the base
h: It's the height
Substituting:

The volume of the pyramid is given by:

Where:
It is the area of the base
h: It's the height
Substituting:

We add and we have:

ANswer:
Option D