Answer: The answer is yes. Students at a high school constitute a group.
Explanation: A group makes reference to a set of people that have an interest or an activity in common. In that way, the members of a group see or hear each other frequently, that is to say that they interact with each other on a regular basis. This is the case of students at a high school since they share an activity: the activity of learning. Furthermore, they have regular contact in one specific place, that is, high school.