Answer:
The correct answer is letter "B": if the marginal benefit of the movie exceeds its marginal cost..
Explanation:
The difference between the marginal benefit and the marginal cost is what determines if businesses should continue to operate or if it is better for them to shutdown. If the marginal benefit is higher than the marginal cost, a firm should keep the business up and running. If the marginal cost is higher than the marginal benefit, there is no reason why the business should continue its operations.
Thus, if the marginal benefit of going to the movies is higher than the marginal cost of paying to go to the movies, you should go and watch a movie.