Respuesta :

the appropriate pronoun is whom, in this case.

Answer:

The correct answer is who.

Explanation:

I was confused with "whom" and "who" until I discovered this helpful trick. Now I'm less confused.

Try substituting “he” and “him”: This man is Robert Howe, he helped me yesterday. This man is Robert Howe, him helped me yesterday. “He” works, so the word you need is who.