Access to the movie 'Casablanca,' which is currently showing in a half-empty theater, is considered a non-rival good. Which of the following options best explains why it is considered a non-rival good?

A) No other movie is available in that theater.
B) When a new movie is released, 'Casablanca' will no longer be available.
C) The number of people watching the movie does not affect others' ability to watch it.
D) The movie can be accessed by multiple people at the same time.