This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Which pa of the lens capsule is thinnest in comparison with other regions of lens? 
Select and explain. 
A. Anterior pa, B. Posterior pa, C. Peripheral pa, D. All of the above
B: Posterior pa
Answer: B: Posterior pa 
Explanation: The lens is composed entirely of epithelium surrounded by a capsule. The lens capsule is a thick, collagenous basement membrane which is transparent, is thickest at the anterior pre equatorial region and thinnest at the posterior pole. The lens epithelium is a single layer of cells lining the capsule. Ref: Parsons' Diseases of the Eye By Ramanjit Sihota & Radhika Tandon, 21st edition, Page 18.