Classification of Metals, Conductors and Semiconductors

Carbon, silicon and germanium have four valence electrons each. These are characterized by valence and conduction bands separated by energy band gap respectively equal to ${\left(\mathit{E}\mathit{g}\right)}_{\mathit{C}}\mathit{,}\mathit{ }{\left(\mathit{E}\mathit{g}\right)}_{\mathit{S}\mathit{i}}$ and ${\left(\mathit{E}\mathit{g}\right)}_{\mathit{G}\mathit{e}}$. Which of the following statements is true?