(A) 512 m3
Given, lateral surface area of a cube = 256 m2
We know that, lateral surface area of a cube = 4 x (Side)2
=> 256 = 4 x (Side)2
=> (Side)2 = 256/4 = 64
=> Side = √64 = 8 m
[taking positive square root because side is always a positive quantity]
Now, volume of a cube = (Side)3
= (8)3
= 8 x 8 x 8
= 512 m3
Hence, the volume of the cube is 512 m3.