Answer:
C. The carbon atoms in graphite are arranged in widely spaced layers.
Step-by-step explanation:
Allotropes are different structural forms of the same element that exist is the same physical state. In other words, they differ in their bonding arrangement.
Carbon has two allotropes: diamond and graphite.
In diamond each C atom is sp3 hybridised and is bonded to 4 other C atoms forming a tetrahedral unit which extends into a crystalline network. In contrast, each C atom in graphite is sp2 hybridised and bonded to 3 other carbon atoms in a crystalline hexagonal layer like structure.
Thus, the carbon atoms in graphite are arranged in widely spaced layers.