Graphite is a soft solid lubricant extremely difficult to melt. The reason for this anomalous behaviour is that graphite

• A

  is an allotropic form of diamond
• B

  has molecules of variable molecular masses like polymers
• Correct answer
  C

  has carbon atoms arranged in large plates of rings of strongly bound carbon atoms with weak interplate bonds
• D

  is a non-crystalline substance

Hence, the correct answer is option: 'C'.