Administrators at a university were interested in estimating the percentage of students who are on a vegetarian diet. The university's student body has about 40, 000 members. How might the administrators answer their question by applying the three Big Ideas? Choose the correct answer below.

a. They should sample a part of the student​ body, selecting respondents with a randomization method. They should be sure to draw a sample of​ 20% of the student body.
b. The administrators should take a census.
c. The administrators should take a survey. They should sample a part of the student​ body, selecting respondents with a randomization method. They should be sure to draw a sufficiently large sample.
d. The administrators should take a survey. They should not use a random method of selecting respondents. They should be sure to draw a sufficiently small sample.