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

• A

  has molecules of variable molecular masses like polymers.
• Correct answer
  B

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

  is a non-crystalline substance.
• D

  is an allotropic form of carbon.

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