A Camera with a Focal Length of 0

Multiple Choice

A camera with a focal length of 0.0500 m (a 50-mm lens) is focused for an object at infinity.To focus the camera on a subject which is 4.00 m away,how should the lens be moved?

A) 1.0 cm closer to the film
B) 0.06 cm closer to the film
C) 4.94 cm closer to the film
D) 0.06 cm farther from the film
E) 4.94 cm farther from the film