Choose the correct statement. In conductors,

Identify the $WRONG$ statement from the following. In an intrinsic semiconductor:

The energy band diagrams for three semiconductor samples of silicon are as shown. We can then assert that

The state of the energy gained by valence electrons when the temperature is raised or when an electric field is applied is called as:

Assertion $(A)$: When a wire of aluminium and another wire of silicon are heated from room temperature to $80^{\circ} C$,the conductivity of aluminium decreases and that of silicon increases.
Reason $(R)$: Aluminium has a positive temperature coefficient of resistivity and silicon has a negative temperature coefficient of resistivity.

At $0 \ K$ temperature,the valence band in semiconductors is .....