Which of the following is a duty of a cosmetology school?

A duty of a cosmetology school is to offer courses that are approved by the State Board of Cosmetology. This is essential because approved courses ensure that students are receiving a standardized education that meets the regulatory requirements set forth by the state. These courses cover necessary skills, safety protocols, and state laws that are critical for future cosmetologists to be successful and compliant in their careers. By providing state-approved education, cosmetology schools prepare students for licensure exams and ensure they are well-equipped to enter the workforce.

The other options do not align with the primary responsibilities of a cosmetology school. Renting space to independent stylists does not pertain to the educational mandates of the school. Conducting services free of charge isn't a standard practice and does not contribute to the school's educational mission. Teaching only advanced techniques excludes foundational training necessary for all students, particularly those who are just starting their cosmetology careers.