You Read the Results of a Survey That Reports That

You read the results of a survey that reports that two-thirds of Cosmopolitan readers lost weight by "going vegan." You should not give the report of this survey much credence because

A) Cosmopolitan readers are disinterested in participating in surveys.
B) readers were not properly assigned to control and experimental conditions.
C) readers who responded to the survey are not likely the same as those who did not.
D) Cosmopolitan readers are overly eager to participate in surveys.