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': 'Shadow test is used in ? \nSelect and explain. \nA. Keratometry, B. Ophthalmoscopy, C. Gonioscopy, D. Retinoscopy', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Retinoscopy Retinoscopy, also called skiascopy or shadow test, is an objective method of finding out the error of refraction by the method of neutralization.", 'role': 'assistant'}]