An n-type of silicon can be formed by adding impurity of:
1. Phosphorous
2. Arsenic
3. Boron
4. Aluminium
Which of the above are correct?

A. Metals B. Semiconductors C. Insulators D. All of the above

A. Drift of holes B. Diffusion of holes C. Drift of electrons D. Diffusion of electrons

A. Both A and R are true and R is correct explanation of A B. Both A and R are true but R is not a correct explanation of A C. A is true but R is false D. A is false but R is true

A. Forward bias voltage B. Potential barrier C. Rate of thermal generation of electron hole pairs D. None of the above