ANSWER
D.
[tex] 140 {units}^{3} [/tex]
EXPLANATION
The volume of a prism is given by:
[tex]Volume = crossectional \: area \times vertical \: height[/tex]
The cross-section of the prism is a triangle.
The area of the cross-section
[tex] = \frac{1}{2} bh[/tex]
[tex] = \frac{1}{2} \times 5 \times 7[/tex]
The height is 8 units.
The volume of the prism
[tex] = \frac{1}{2} \times 5 \times 7 \times 8[/tex]
[tex] = 140 {units}^{3} [/tex]
