Carbon, Silicon and Germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by $(E_g){_c}$ $(E_g)_Si$and $(E_g)_Ge$ respectively. Which one of the following relationships is true in their case .

Question

( A ) $(E_g){_c}<(E_g){_Ge}$ <br/> ( B ) $(E_g){_c}=(E_g){_Si}$
( C ) $(E_g){_c}<(E_g){_Si}$ <br/> ( D ) $(E_g){_c}>(E_g){_Si}$