Answer
A. 63 m³
Step-by-step explanation:
The volume of the prism is equal to
V = Bh
Where B is the area of the base and h is the height of the prism.
In this case, the base is triangular, so the area of the base is equal to

Then, the volume of the prism is equal to
V = (9 m²)(7 m)
V = 63 m³
Therefore, the answer is
A. 63 m³