Answer:
The answer is C.
Step-by-step explanation:
The terms "in-group", "out-group" etc. belong in to the sciences of sociology or psychology and they indicate a group setting where some people are in line with the requirements of belonging in that group and some are not. The sociologist states that he/she is studying the first-graders and when we examine the options according to the out-group description above after reading the question, the first-graders would be providing an example of out-group if they said "Ms. Alexander's students are the worst!".
I hope this answer helps.