Answer:
D. people leaving a movie theater
Explanation:
If you choices are the following:
A: all students who go to the movies
B: teenagers waiting on line at the movie theater
C: 100 names randomly selected from the phone book
D: people leaving a movie theater
When selecting a sample for a study, you first need to consider the purpose of the study to really determine what population would give you reliable results. Secondly, the population you will consider needs to be relevant to your study as well. A random sample does not necessarily mean you can just pick anyone.
People leaving a movie theater would be a good random sample because they could consist of people of different ages and different preferences, making this ideally random.