Actually this question options C will be correct bcoz, option A, B, d didnt make any sense or unuseful for given question statement, so can say fermi level will be same as previous if we didnt vary these a,b

Introduction:
In an n-type semiconductor, the majority charge carriers are electrons, which are introduced by doping the semiconductor material with donor atoms. The concentration of donor atoms determines the number of electrons available for conduction. The Fermi level (EF) represents the energy level at which the probability of finding an electron is 0.5. In an n-type semiconductor, the Fermi level is typically located closer to the conduction band.

Explanation:
As the temperature of an n-type semiconductor increases, the Fermi level (EF) tends to move towards the conduction band. This can be explained by the following factors:

1. Effect of Increasing Temperature:
- Increasing the temperature in a semiconductor causes the thermal energy of the electrons to increase.
- This increased thermal energy allows some of the electrons in the valence band to overcome the bandgap and move into the conduction band.
- As more electrons move into the conduction band, the Fermi level, which represents the energy level at which the probability of finding an electron is 0.5, shifts towards the conduction band.

2. Energy Level Distribution:
- At absolute zero temperature (0K), all energy levels below the Fermi level are filled with electrons, while all energy levels above the Fermi level are empty.
- As the temperature increases, the distribution of energy levels becomes broader due to the increased thermal energy.
- This broadening of energy levels leads to a partial occupation of energy levels above the Fermi level.
- The increase in temperature causes more electrons to occupy energy levels closer to the conduction band, thereby shifting the Fermi level towards the conduction band.

3. Concentration of Donor Atoms:
- The concentration of donor atoms in an n-type semiconductor affects the position of the Fermi level.
- If the concentration of donor atoms is high, there are more electrons available for conduction.
- As the temperature increases, the increased thermal energy allows more electrons to occupy higher energy levels, causing the Fermi level to move towards the conduction band.
- However, if the concentration of donor atoms is low, the number of available electrons for conduction is limited, and the Fermi level may not shift significantly towards the conduction band with increasing temperature.

Conclusion:
In an n-type semiconductor, as the temperature increases, the Fermi level (EF) generally moves towards the conduction band. This is a result of the increased thermal energy of the electrons, the broadening of energy levels, and the concentration of donor atoms. However, the actual shift of the Fermi level depends on the concentration of donor atoms in the semiconductor material.