Answer:
The 200 students constitute Amy's sample. The people to whom she assumes her results will generalize are called the population.
Explanation:
When conducting a survey or a study, we will apply the findings to a population, that is, a specific group of people. In this case, Amy's population is quite large: young adults. Since it would be impossible for Amy to conduct the survey with the whole population of young adults, she does it with only a part of it, a subgroup of the population called the sample. From her findings with the sample, Amy will generalize her conclusions to the whole population of young adults.