Carbon, silicon and germanium have four valence electrons each. At room temperature which one of the following statements is most appropriate?

• A. The number of free electrons for conduction is significant only in \[Si\] and \[Ge\] but small in C.
• B. The number of free conduction electrons is significant in C but small in \[Si\] and \[Ge\].
• C. The number of free conduction electrons is negligibly small in all the three.
• D. The number of free electrons for conduction is significant in all the three.