Final answer:
In general, people are required to check their DOT email once per day.
Step-by-step explanation:
The question pertains to checking a DOT email, which is related to Computers and Technology. The frequency at which one is required to check their DOT email depends on the specific organization's policies and requirements. However, a common practice is to check one's email at least once per day, which is the answer choice c in the question.