The forbidden energy band gaps in conductors,semiconductors,and insulators are $E_{G1}$,$E_{G2}$,and $E_{G3}$ respectively. The relation among them is:

• A
  $E_{G1} = E_{G2} = E_{G3}$
• B
  $E_{G1} < E_{G2} < E_{G3}$
• C
  $E_{G1} > E_{G2} > E_{G3}$
• D
  $E_{G1} < E_{G2} > E_{G3}$