4. What's the name of that film producer ___ film you were watching last night? A who's B whose C whom

The correct answer is B whose. 'Whose' indicates possession or a relationship. Explanation: * 'Who's' is a contraction of 'who is' or 'who has'. * 'Whom' is used as the object of a verb or preposition. * 'Whose' is appropriate here because it relates the film producer to the film.