(A-III) hear about = receive news/information on a topic (not directly from a person).
→ “Did you hear about what happened at the party…?”
(B-I) complain of = say you are suffering from an illness/pain (medical sense).
→ “Mega was complaining of pain in her knee…”
(C-IV) apologize for = say sorry for an action/mistake you did.
→ “Are you going to apologize for what you did?”
(D-II) suffer from = be affected by an illness/problem.
→ “She suffers from severe headache.”