Dr. Buhle, a health psychologist, is interested in the exercise intentions of students on her campus. She surveys 1,000 students about whether they intend to exercise regularly in the near future. One potential problem with this method is that:

A. it is an expensive and time-consuming method.
B. the intention to exercise can mean different things to different people.
C. it cannot be used effectively with other research methods.
D. almost everyone in her sample will likely lie.