This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Orbit and Adnexa, Subject name: Ophthalmology
[{'content': "Which of the following is sign named for infrequent blinking of eyelids in grave's ophthalmopathy \nSelect and explain. \nA. Enroth sign, B. Stellwag sign, C. Gifford's sign, D. Vongraefe sign", 'role': 'user'}, {'content': "Answer: B \nExplanation: Infrequent Blinking : Stellwag sign Grave's Ophthalmopathy Signs Enroth sign - 'e' for edemameans fullness of eyelids. Joffroy sign- absent creases in the forehead on superior gaze. Grove sign- resistance to pulling down the retracted upper lid. Stellwag sign- incomplete and infrequent blinking - still meaning 'no movement'. Ballet sign- restriction of one or more extraocular muscles. Gifford sign- difficulty in eveing upper lid Jellink's sign Increased pigmentation on the lids IOP is increased in up-gaze. Von Graefe's sign - Lid lag", 'role': 'assistant'}]