Two ad agencies want to understand issues that are important to students. agency a will interview 50 students whose names are randomly chosen from school enrollment data. agency b will interview 50 randomly selected people from those who respond to a social media posting. which method will produce a fair sample of the student population and why?
a. agency a, because students are convenient and easy to interview
b. agency a, because names randomly selected from school data will be student names
c. agency b, because people who respond to social media postings have strong opinions
d. agency b, because people who respond to social media postings are usually students

These ad agencies must focus on their target audience, which are the students. Hence, they should gather data on the pool that will surely comprise of students. For agency B, social media posting is not a good source pool. It's true that students are very participative and opinionated in social media. However, they can't be sure that these are students. Some parents are in social media, as well. Some are working individuals, and some are out of school youth. Unlike agency A, agency B has to sort out profiles first and identify which ones are students. Hence, agency A will produce a fair sample of the student population because it is unarguably true that everyone in the school enrollment data are students.

The answer is B.