Question

How does the volume of a prism change if each dimension of the prism is doubled?

Answer 1

Correct!

V = A*h;
A ---> (2*2)A;
h ---> 2h;

V ---> (2*2*2)V = 8V.

Answer 2

The prism has 3 dimensions. So, if you double the linear sizes ("dimensions") the volume is multiplied by $2^3=8$.