A. Whom he is looked after for?
B. Who is looked after for him?
C. Who is looked for by him?
D. Whom he looked after by?
Rule :
Who + helping verb + Subject + V3 + Other objects + ?(question mark).
A. Whom he is looked after for?
B. Who is looked after for him?
C. Who is looked for by him?
D. Whom he looked after by?
Rule :
Who + helping verb + Subject + V3 + Other objects + ?(question mark).