Which of the following makes up a film's soundtrack during the post-production process?

Background music only

Actors' dialogue only

Actors' dialogue and the film's sound effects

Actors' dialogue, sound effects, and background music

I believe the correct answer is the last statement: Actors’ dialogue, sound effects, and background music.

Actors’ dialogue, sound effects, and background music make up a film’s soundtrack during the post-production process. Audio post-production is general term for all the stages of production from actual recording to completion of a master recording which involves sound design, sound editing, audio mixing, and the addition of effects. Sometimes the original dialogs lacks in performance or quality, and the actor is brought into a sound studio to record again. The foley, music, and voiceover, are also added during post production.