The capacity of the box would be the volume.
Multiply the area by the height:
4x^2 + 8 times x+2
Multiply each term by each term:
4x^2 * x = 4x^3
4x^2 * 2 = 8x^2
8 * x = 8x
8*2 = 16
Combine the terms to get:
4x^3 + 8x^2+ 8x +16
The answer is A. C(x) = 4x^3 + 8x^2 + 8x + 16