Read this paragraph. The clock ticked menacingly as the students’ pencils scratched the tests. An exasperated sigh leaked out from a far corner, while a determined elbow pounded a desk in the front row. Several fingernails were gnawed, and sweat beaded on many brows. The teacher announced, “Five minutes remaining,” and one student squeezed her eyes closed in a prolonged blink.

What do the descriptive details reveal?

the tension in the room
the subject of the test
the teacher’s emotions
the students’ thoughts