This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Strabismus, Subject name: Ophthalmology
In case of Ptosis which cranial nerve will be completely paralyzed 
Select and explain. 
A. 3rd CN palsy, B. 4th CN palsy, C. 5th CN palsy, D. 6th CN palsy
A: 3rd CN palsy
Answer: A: 3rd CN palsy 
Explanation: Ans. (a) 3rd CN palsyRef: A.K. Khurana 6th ed. /379* Ptosis is drooping of eyelid.* Eyelid is comprised of 4 muscles:Muscles, their innervation and functionMuscleCN innervationFunctionLPSIIIOpens the eyelidMuller's muscleIIIOpens eyelid when LPS tiredFrontalisVIICloses the eyelidOrbicularis oculiVIICloses the eyelid* CN III palsy leads to drooping of eyelid (Ptosis).* CN VII palsy may also cause ptosis.Also Know* All the extraocular muscles are supplied by CN III except lateral rectus and superior oblique.* Lateral rectus supplied by- CN VI* Superior oblique supplied by- CN IVRemember- LR6, S04; all other by CN III