Carbon, silicon and germanium have four valence electrons each. These are characterised by valence and conduction bands separated by energy band gap respectively equal to $\left(\mathrm{E}_{\mathrm{g}}\right)_{\mathrm{C}},\left(\mathrm{E}_{\mathrm{g}}\right)_{\mathrm{Si}}$ and $\left(\mathrm{E}_{\mathrm{g}}\right)_{\mathrm{Ge}}$. Which of the following statements is true?
(a) $\left(\mathbf{E}_{\mathrm{g}}\right)_{\mathrm{Si}} < \left(\mathbf{E}_{\mathrm{g}}\right)_{\mathrm{Ge}} < \left(\mathbf{E}_{\mathrm{a}}\right)_{\mathrm{C}}$
(b) $\left(\mathbf{E}_{\mathrm{g}}^{\mathrm{s}}\right)_{\mathrm{C}} < \left(\mathbf{E}_{\mathrm{g}}^{\mathrm{g}}\right)_{\mathrm{Ge}} < \left(\mathbf{E}_{\mathrm{g}}^{\mathrm{g}}\right)_{\mathrm{Si}}$
(c) $\left(\mathbf{E}_{\mathrm{g}}^{\mathrm{z}}\right)_{\mathrm{C}}>\left(\mathbf{E}_{\mathrm{g}}\right)_{\mathrm{Si}}>\left(\mathbf{E}_{\mathrm{g}}\right)_{\mathrm{Ge}}$
(d) $\left(\mathbf{E}_\rho^{\mathrm{s}}\right)_{\mathrm{C}}=\left(\mathbf{E}_\rho^{\mathrm{s}}\right)_{\mathrm{St}}=\left(\mathbf{E}_\rho^{\mathrm{s}}\right)_{\mathrm{Ce}}$