The built-in potential (diffusion potential) in a p-n junction
1. is equal to the difference in the Fermi-level of the two sides, expressed in volts.
2. increases with the increase in the doping levels of the two sides.
3. increases with the increase in temperature.
4. is equal to the average of the Fermi-levels of the two sides.
Which of the above statements are correct?

A. 1 and 2 only

B. 1 and 3 only

C. 1, 2 and 3

D. 2, 3 and 4

Answer: Option C