This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Eye, Nose and Ear, Subject name: Anatomy
[{'content': 'The arrow marked structure is ? \nSelect and explain. \nA. Macula, B. Utricle, C. Saccule, D. Endolymphatic sac', 'role': 'user'}, {'content': 'Answer: D \nExplanation: - The diagram is showing inner ear & the arrow marked structure is endolymphatic sac .', 'role': 'assistant'}]