This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ocular trauma , Subject name: Ophthalmology
[{'content': 'Commotio retinae affects which pa of retina - \nSelect and explain. \nA. Posterior pole, B. Peripheral retina, C. Inferior-nasal pa, D. Superior-nasal pa', 'role': 'user'}, {'content': "Answer: A \nExplanation: Commotio retinae (Berlin's oedema): It is of common occurrence following a blow on the eye. It manifests as milky white cloudiness involving a considerable area of the posterior pole with a 'cherry-red spot' in the foveal region. It may disappear after some days or may be followed by pigmentary changes. Ref: AK Khurana 4thE pg 406", 'role': 'assistant'}]