This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
When a stretch reflex occurs the muscles that antagonize the action of the muscle involved relaxes. This phenomenon is known as: 
Select and explain. 
A. Inverse stretch reflex, B. Reciprocal innervation, C. Autogenic inhibition, D. Lenthening reaction
B: Reciprocal innervation
Answer: B: Reciprocal innervation 
Explanation: Reciprocal innervation is a phenomenon in which, when a stretch reflex occurs the muscles that anotogonize the action of the muscle involved relaxes. The pathway mediating this effect is bisynaptic. Golgi bottle neurons (inhibitory interneurons) are involved in this phenomenon. Ref:Ganong's Review of Medical Physiology, 21st Edition, Page 133