This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Channelopathies and Neuropathies, Subject name: Medicine
1st symptom to respond to IV Thiamine in Wernicke's encephalopathy is? 
Select and explain. 
A. Opthalmoplegia, B. Sensory Ataxia, C. Vestibular ataxia, D. Global confusion
A: Opthalmoplegia
Answer: A: Opthalmoplegia 
Explanation: Wernicke's encephalopathy * Global Confusion * Ophthalmoplegia: VI N. * Ataxia - Rx- IV Thiamine -First to respond to treatment - Ophthalmoplegia