Who of the following most likely is an independent contractor?

Who of the following most likely is an independent contractor?
A . A repairman who is called periodically to perform maintenance on the PC’s of a dental office.
B. A person normally employed in the mail room who comes in after hours to clean the offices.
C. A commissioned salesman who works from his home.
D. A retiree called back to work on a temporary basis

Answer: A