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': 'Kamla, age 48 yrs, presents with unilateral mild axial proptosis. There is no redness or pain. Investigation of choice is : \nSelect and explain. \nA. T3 &T4 measurements to rule out thyrotoxicosis, B. CT scan to rule out meningioma, C. Doppler to rule out hemangioma, D. USG to rule out orbital pseudotumor', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. T3 & T4 measurement to rule out thyrotoxicosis', 'role': 'assistant'}]