A Movie Theater has $4$ theaters to show $3$ movies with runtimes as follows: Movie A is $120$ minutes, Movie B is $90$ minutes, Movie C is $150$ minutes. The runtime includes the break between any two movies. The capacity of the four theaters, in number of seats, are: $500,300,200$ and $150.$ The popularity of each movie is such that any theater will be at $70\%$ of capacity for Movie A$,60\%$ of capacity for Movie B$,$ and $80\%$ of capacity for Movie C$.$ Each theater can operate for a maximum of $900$ minutes every day. Each theater should show each movie at least once. Each movie should have a minimum number of screenings each day: $5$ for Movie A; $4$ for Movie B; $6$ for Movie C$.$ Create a model to maximize the number of spectators. We achieve the optimum solution by changing which of the following parameter?

A$.$

Number of screenings

B$.$

Number of spectators

C$.$

Run time of the movies

D$.$

Both A and B

E$.$

Both B and C