Answer:
C
Explanation:
Remark
The way to solve the problem is to figure out how many cubic feet would be present if the window was not there and then calculate the volume of the window and subtract it. That is the general method used to obtain the answer to the question you have asked.
Volume Original Shape
Each side of the figure is one side of a square.
So the volume of the square face is 6 by 6 or 6*6 = 36 (no window)
The window is 2*2 which is 4.
The volume of the original shape is 36 - 4 = 32
Volume new shape
Each side of the figure is 12 by 12 = 144 With no window
The size of the window is 4 by 4 = 16 With the window (Subtract)
The size of the modified figure is 128
Answer and discussion
The question is a bit ambiguous. I think the question means that the wall has gone from 32 to 128 cubic feet. So you need Subtract to find the difference..
Answer: 128 - 32 = 96 which is C.