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
Features of pyramidal tract lesion are all except 
Select and explain. 
A. Clasp knife rigidity, B. Involuntary movements, C. Positive Babinski sign, D. Exaggerated reflexes & increased tone
B: Involuntary movements
Answer: B: Involuntary movements 
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.