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
According to Sherrington, the decerebrate rigidity is characterized by all except 
Select and explain. 
A. Rigidity occurs in all muscles of body, B. Increase in rate of g motor neuron discharge, C. Decerebration produces no phenomenon akin to spinal shock, D. Increased excitability of motor neuron pool
A: Rigidity occurs in all muscles of body
Answer: A: Rigidity occurs in all muscles of body 
Explanation: The Decerebrate Animal Develops Spastic Rigidity when the brain stem of an animal is sectioned below the midlevel of the mesencephalon but the pontine andmedullary reticular systems, as well as the vestibular system, are left intact, a condition called decerebrate rigidity develops. This rigidity does not occur in all the muscles of the body, but it does occur in the antigravity muscles-- the muscles of the neck and trunk and the extensors ofthe legs.The cause of decerebrate rigidity is blockage of normally strong input to the medullary reticular nuclei from the cerebral coex, the red nuclei, and the basal ganglia.Lacking this input, the medullary reticular inhibitor system becomes nonfunctional, full overactivity of the pontine excitatory system occurs, and rigidity develops.Guyton 13th edition Pg: 714