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: Anatomy
[{'content': 'Ipsilateral deviation of tongue in 12th nerve palsy is due to - \nSelect and explain. \nA. Unaltered action of ipsilateral genioglossus, B. Unaltered action of contralateral genioglossus, C. Action of hyoglossus, D. Action of lateral pterygoid', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Injury to hypoglossal (12th) nerve paralyzes ipsilateral half of the tongue. When the tongue is protruded, its tip deviates towards the paralyzed side because of unopposed action of genioglossus muscle on the normal side of the tongue.', 'role': 'assistant'}]