Answer
See the answer below.
Work Step by Step
p-type: Doping a Group 4A element with a Group 3A creates an acceptor energy level between the valence band and the conduction band, which can accept electrons from the former.
n-type: Doping a Group 4A element with a Group 5A creates a donor energy level between the valence band and the conduction band, which can donate electrons to the latter.
a) Ge (4A) with As (5A): n-type
b) Si (4A) with P (5A): n-type
c) Ge (4A) with In (5A): n-type
d) Ge (4A) with Sb (5A): n-type
