Attendance at movie theaters declined in the 1950s due to the
depressed economy
popularity of tv
high price of movie tickets
enforcement of the production code

Attendance at movie theaters declined in the 1950s due to the popularity of TV.

Explanation:

The emergence of quality TV shows produced by different broadcasters fetched the attention of the majority population of the United States. Moreover, the movie theaters failed to dispense the comfort and convenience that watching TV while sitting at home offered. The shows that were broadcasted on the TV were light and comedy. Also, they did not even restrict the viewer to one place for long hours. These traits were preferred by the viewers and hence, the attendance at the movie theaters declined during the period.

Answer is mass marketing.