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': 'Vossius ring is seen in the - \nSelect and explain. \nA. Cornea, B. Anterior capsule of the lens, C. Posterior capsule of the lens, D. Iris', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Vossius ring is a circular ring of brown pigment seen on the anterior capsule of the lens. It occurs due to striking of the contracted pupillary margin against the crystalline lens. It is always smaller than the size of pupil.', 'role': 'assistant'}]