If we collect information on students' study practices and exam scores and find strong evidence of a positive association between not studying more than two hours and high grades, when can we generalize this finding to the general population?

A student list for the college was obtained and students were randomly selected from the list to participate.

Explanation:

When the we select them randomly based on the test subject population, we can make a safe assumption that those random selection actually represent the real life demographic of the general population. If we select them manually, we will create a risk of biased pick  (the selected could have similar characteristics that the researchers personally like)

there are no options provided but you can choose among the following gender-neutral pronouns: zir, hir, eir, vis, tem, eir.

in the normal course of maintaining a pronoun-antecedent agreement, we could have used the words his or her but since we are also required to use gender-neutral language, we need to replace it with its equivalent gender-neutral pronoun.