Ahmed Abdelhafeez posted:
"I met a woman......I found very inte[r]esting."
A-which b-whom c-that
You can use (b) ("whom"), (c) ("that"), or (d -- the unmentioned choice) (nothing):
(b) I met a woman whom I found very interesting.
(c) I met a woman that I found very interesting.
(d) I met a woman I found very interesting.
The only incorrect choice is (a) ("which"). In modern English, "which" is not used with human antecedents. Incidentally, you will hear and see native English speakers using "who" instead of "whom" in such sentences.