Final answer:
A school of cosmetology should have a minimum of 1 hair dryer per student.
Step-by-step explanation:
In a school of cosmetology, the minimum number of hair dryers required would depend on the size of the school and the number of students. However, as a general guideline, it is recommended to have at least 1 hair dryer per student.
So, if there are 10 students, you would need a minimum of 10 hair dryers (option A). This ensures that each student has access to a hair dryer during practical sessions.