Carbon, silicon and germanium atoms have four valence electrons each. Their valence and conduction bands are separated energy band gaps represented $\left(E_g\right)_C,\left(E_g\right)_{S i}$, and $\left(E_g\right)_{G e}$ respectively. Which one of the following relationship is true in their case?

• Correct answer
  A

  $\left.\left(\mathrm{E}_g\right)_{\mathrm{C}}>\mathrm{E}_g\right)_{\mathrm{Si}}$
• B

  $\left.\left(\mathrm{E}_g\right)_{\mathrm{C}} < \mathrm{E}_g\right)_{\mathrm{Si}}$
• C

  $\left.\left(\mathrm{E}_g\right)_{\mathrm{C}}=\mathrm{E}_g\right)_{\mathrm{Si}}$
• D

  $\left(\mathrm{E}_g\right)_{\mathrm{C}}>\left(\mathrm{E}_g\right)_{\mathrm{Ge}}$

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