Answer:
E. The new volume is 27 times the old volume.
Explanation:
A rectangular prism has dimensions width w, height h and length l. It's volume is given by:

Edges of a rectangular prism are increased by a scale factor of 3
Each dimensions is multiplied by 3, and the volume is:

How will the volume change?

Thus, the volume is multiplied by 27, that is, it is 27 times the old volume, and the correct answer is given by option E.