Answer
See answers.
Work Step by Step
a. This reaction is possible. Conservation laws are satisfied.
b. This reaction is impossible. Conservation of charge is violated: $1+1 \neq 0 + 0$.
c.. This reaction is impossible. Conservation of lepton number is violated: $0+0 \neq 0 + 1$.
d. This reaction is impossible. Conservation of baryon number is violated: $1 \neq 0 + 0$.
e. This reaction is impossible. Conservation of lepton number is violated: $0 \neq -1 + 0$.
f. This reaction is impossible. Conservation of energy is violated:
$$938.3 MeV/c^2 \lt 939.6 MeV/c^2+0.511 MeV/c^2$$