Final answer:
Cosmetologists must be licensed to practice professionally, which involves education, exams, and adherence to health and safety standards.
Step-by-step explanation:
In addition to attending school, a cosmetologist must be licensed to work as a professional. The correct answer is A) Licensed. Each state in the United States requires cosmetologists to obtain a license to legally provide cosmetology services, which typically includes a combination of education, examinations, and sometimes continuing education to maintain the license. This process ensures that professionals meet certain standards of competency and adhere to health and safety regulations.