Final answer:
The professor would likely reprimand or admonish their students for not studying for the exam, as both terms indicate disapproval, whereas praise would be inappropriate.
Step-by-step explanation:
If a professor's students did not study for an exam, they would most likely reprimand or admonish them rather than praise or laud. A reprimand is a formal expression of disapproval, usually for a serious infraction, while to admonish is to warn or reprimand someone firmly, often for a less serious issue.
In the scenario provided, the professor may admonish the student who is talking on their cell phone during class by asking them to turn it off, as a form of maintaining social control. In contrast, praise or laud would be inappropriate actions for a professor to take when students have failed to prepare for an exam.