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
Following are the features of corticospinal involvement except 
Select and explain. 
A. Cog-wheel rigidity, B. Spasticity, C. Plantar extensor response, D. Exaggerated deep tendon reflexes
A: Cog-wheel rigidity
Answer: A: Cog-wheel rigidity 
Explanation: Babinski sign is the sure sign of pyramidal tract/corticospinal lesion.
Spasticity and exaggerated tendon reflexes are due to extrapyramidal lesions. 
Since pyramidal lesion occurring alone is rare, extrapyramidal lesions also may be seen. Rigidity seen is clasp knife type.