Choose the only false statement from the following:

• A

  In conductors the valence and the conduction bands overlap.
• B

  Substance with energy gap of the order of $10 \mathrm{eV}$ are insulators.
• Correct answer
  C

  The resistivity of a semiconductor increases with increase in temperature.
• D

  The conductivity of a semiconductor increases with increase in temperature.

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