The expression (x−3)(x+3)(3x) represents the volume of a rectangular prism, where x−3 is the width, x+3 is the length, and 3x is the height.

The value of x is tripled. Which statement must be true about the new prism?

A
The volume is tripled.

B
The width is tripled.

C
The length is tripled.

D
The height is tripled