What is the volume of the given cuboid? Area of each side of smaller cube is $1c{m}^2$.

The correct option is D $8c{m}^3$
Given:
Area of the side of the cube, $A=1c{m}^2$.
Cuboid is made of the given cubes.

Side of a cube is a square. Area of sqaure is given by:
$A=a^2$
where $a$ is the length of the side of the square.
$1c{m}^2=a^2$
$a=1cm$

Hence side length is $1cm$. This is also the length of the side of the cube.

Volume of a cube is given by:
$V=a^3$
$V=1^{3}c{m}^3=1c{m}^3$

The given cuboid consists of $8$ smaller cubes.
So, the volume is:
$V^{\prime }=8\times 1c{m}^3=8c{m}^3$