`C` and `Si` both have same lattice structure, having `4` bonding electrons in each. However, `C` is insulator whereas `Si` is intrinsic semiconductor. This is because

Options

A. In case of C, the valence bond is not completely filled at absolute zero temperature
B. in case of C, the conduction band is partly filled even at absolute zero temperature
C. the four bonding electrons in the case of C lie in the second orbit, whereas in the case of Si they lie in the third
D. the four bonding electrons in the case of C lie in the third orbit, whereas for Si they lie in the fourth orbit

Answer

C