This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Physiology
[{'content': "According to Sherrington model of decerebrate rigidity is characterised by all except \nSelect and explain. \nA. Rigidity occurs all muscles of the body, B. Increased in the rate of discharge of the 'y' efferent neuron, C. Increased excitability of the motor neuron pool, D. Decerebration produces no phenomenon akin to spinal shock", 'role': 'user'}, {'content': 'Answer: A \nExplanation: A key feature of this decerebrate animal was that when the dorsal roots of spinal cord were cut ( differentiation ) the rigidity disappeared, showing that the cause of rigidity was a hyperactive stretch reflex in the antigravity muscles. (REF: TEXTBOOK OF MEDICAL PHYSIOLOGY GUYTON AND HALL, 12e Page no 779)', 'role': 'assistant'}]