Stephanie Conducts an Experiment to Test Whether Dramas or Comedies

Multiple Choice

Stephanie conducts an experiment to test whether dramas or comedies are more popular amongst the general population. She surveys a sample of 100 people who walk past the student union building that evening between 5 and 8 pm. Just before finishing her data collection, she overhears someone talk about the comedy improve show that just happened in the student union building. She realizes that her results may be invalid due to

A) measures that were not obtrusive enough
B) a poorly defined population
C) a fourth variable
D) measures that were too obtrusive
E) a confounding of variables