For an intrinsic semiconductor at temperature $\text{T}=0 \; \text{K}$, which of the following statement is true?
- All energy states in the valence band are filled with electrons and all energy states in the conduction band are empty of electrons.
- All energy states in the valence band are empty of electrons and all energy states in the conduction band are filled with electrons.
- All energy states in the valence and conduction band are filled with holes.
- All energy states in the valence and conduction band are filled with electrons.