Correct Answer: Graphite

Solution : The correct option is - Graphite

The material used in the manufacture of a lead pencil is a mixture of graphite and clay.The core of a pencil is made by grinding a mixture of graphite and clay into a fine powder. The proportions of graphite to clay can vary, affecting the hardness or softness of the pencil.This mixture is then mixed with water and various additives, and then extruded through a machine to form long, thin rods. These rods are then dried and cut into the familiar pencil length.