The correct option is C 4a2
Lateral surface area of a cube is the sum of areas of 4 of its faces, excluding the areas of top and bottom faces.
The area of each face of a cube of side 'a' is a2.
⟹ The sum of areas of 4 faces = 4a2
∴ Lateral surface area of a cube of side 'a' is equal to 4a2 .