In the patellar reflex which component serves as the receptor

Quadriceps spindle is the receptor. The patellar reflex is also called a knee-j erk reflex. In a knee-j erk reflex arc the sensory neuron directly connects to the motor neuron in the spinal cord. This is called a simple reflex arc. from the spindle to where it connects with the motor neuron in the spinal cord.

I’m going to go with b!