Final answer:
PTAs must be supervised by a licensed Physical Therapist (PT), as PT students and PTLAs do not have the authority to provide supervision.
Step-by-step explanation:
Physical Therapist Assistants (PTAs) must work under the direction and supervision of a licensed Physical Therapist (PT). PTs are highly educated professionals with a master's degree or doctorate, specializing in the mechanics of body movements and often focusing on treating sports injuries. Therefore, the correct answer to the question 'PTAs can be supervised by' is C) A licensed PT (Physical Therapist). PT students and Physical Therapist License Applicants (PTLAs) do not have the qualifications or the legal standing to supervise PTAs as they are either still in training or awaiting licensure.