Answer:
C. Changeable lenses of different focal lengths allow light to enter the camera, which then forms the image on light-sensitive film.
Step-by-step explanation:
A is not an option, as the opening is always adjustable. And B is also not an option opening is never light sensitive. And C seems to be correct as changeable lenses of the different focal lengths are the correct option, and it certainly allows light to enter the camera, which then forms the image on the light-sensitive film.