After witnessing an assistive personnel (AP) using an incorrect procedure when transferring a client with a mechanical lift, and reinforcing proper procedure, which of the following methods should the nurse manager use to evaluate the AP's understanding of the teaching?

A) Observing the AP during multiple client transfers to ensure correct technique.
B) Providing a written test on mechanical lift procedures for the AP to complete.
C) Asking the AP to demonstrate the correct procedure during a simulated transfer.
D) Informing the AP that no further evaluation is necessary after the reinforcement.