This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Uveal Tract, Subject name: Ophthalmology
Persistent pupillary membrane originates from 
Select and explain. 
A. Collarette, B. Angle of ant. chamber, C. Around pupil, D. Root of iris
A: Collarette
Answer: A: Collarette 
Explanation: Ans. (a) CollaretteRef: Paediatric Ophthalmology by Wright and Speigel, p. 444PPM is the most common developmental abnormality of the iris. They are believed to the vestiges of precursor vessels and associated structures derived from tunica vasculosa lentis.The formation of a PPM is a normal embryological process and starts at the Iris Collarette (thickest part of the iris).