This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of orbit, Lids and lacrimal apparatus, Subject name: Ophthalmology
The most common cause of proptosis in adults is 
Select and explain. 
A. Preseptal cellulitis, B. Orbital cellulitis, C. Thyroid eye disease, D. Capillary hemangioma
C: Thyroid eye disease
Answer: C: Thyroid eye disease 
Explanation: Proptosis:- Ref:- A K Khurana Comprehensive Ophthalmology 7th edition; pg num:- 398