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: Social & Preventive Medicine
Classic sign of lead induced peripheral neurotoxicity is: 
Select and explain. 
A. Loss of vibration sense, B. Paraesthesia, C. Anaesthesia, D. Foot drop
D: Foot drop
Answer: D: Foot drop 
Explanation: Lead-induced pathological changes in these fibres include segmental demyelination and axonal degeneration. Extensor muscle palsy with wrist and ankle drop has been recognized since the time of Hippocrates as the classic clinical sign of the peripheral neurological toxicity of lead; however, this generally only occurs with chronic lead poisoning and is rare in acute exposure to lead. Ref :