Why might the method used be biased? Asking every twentieth student does not accurately represent the student population. It is likely that student opinions in one particular high school do not accurately represent the opinions of all high school students. Students that take the time to complete the survey and mail it in probably feel strongly about hot lunches.

B). It is likely that student opinions in one particular high school do not accurately represent the opinions of all high school students.

C). Students that take the time to complete the survey and mail it in probably feel strongly about hot lunches.

Explanation:

As per the given description of the study, the method could be considered bias as the inclination towards collecting data from the nearest high school may influence the accuracy and efficacy of the results or judgment. The student taking time would prevent a natural study as there are chances of the student receiving false or untruth information. Thus, it is always recommended that the sample (for survey or test) a must be selected randomly (a not selectively) and the conduct on-the-spot survey for collecting true data in order to achieve an objective, generalized, and substantial results/deductions. Thus, options B and C are the correct answers.