When a Physician Taps the Patellar Tendon with a Hammer

Multiple Choice

When a physician taps the patellar tendon with a hammer, it causes a knee jerk reflex by sending stretch signals to:

A) motor neurons in the spinal cord that cause muscles to contract.
B) motor neurons in the cortex that cause muscles to contract.
C) the thalamus, which sends signals to motor neurons to contract.
D) the cerebellum, which sends signals to motor neurons to contract.