Your friend remarks that longer movies are a better deal than shorter movies because the ticket price is the same in both cases. Therefore, the longer movie provides more benefit for the same cost as a shorter movie. Which of the following is the best argument against your friend's claim that longer movies provide more benefit than shorter movies?

Based on the:

a. opportunity cost principle, the length of the movie does not matter as long as watching a movie is the best way to spend your time compared to other alternatives.
b. cost-benefit principle, the benefits of a longer movie exceed the costs when compared to a shorter movie.
c. marginal principle, you should only continue to watch an additional movie if it is shorter than the first movie.
d. interdependence principle, longer movies are affected by the market for shorter movies.