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
Enophthalmos is due to plasy of- 
Select and explain. 
A. Levator palpebrae superioris, B. Superior tarsal muscle, C. Orbitalis muscle, D. Tenon's Capsule instability
D: Tenon's Capsule instability
Answer: D: Tenon's Capsule instability 
Explanation: *Tenon's capsule instability is a major cause of enophthalmos, as it forms all the major ligament of the orbit which suppo the globe in the orbit. Ref: Duane's Clinical ophthalmology, vol.2, chapter 48, p.5