This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
All of the following clinical findings are seen in Horner's syndrome, except 
Select and explain. 
A. Miosis, B. Anhidrosis, C. Heterochromia of iris, D. Apparent exophthalmos
D: Apparent exophthalmos
Answer: D: Apparent exophthalmos 
Explanation: The triad of miosis with ipsilateral ptosis and anhidrosis constitutes Horner&;s syndrome, although anhidrosis is an inconstant feature. Brainstem stroke, carotid dissection, and neoplasm impinging on the sympathetic chain occasionally are identified as the cause of Horner&;s syndrome, but most cases are idiopathic.(Ref: Harrison's 18/e p 225)