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: Ophthalmology
[{'content': 'Weight of an adult eyeball is: \nSelect and explain. \nA. 7 g, B. 9 g, C. 11 g, D. 13 g', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. 7 g', 'role': 'assistant'}]