This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Lens), Subject name: Ophthalmology
Lens contains the oldest cells in 
Select and explain. 
A. nucleus, B. anterior surface of lens, C. posterior surface of lens, D. Nucleo-cortical junction
A: nucleus
Answer: A: nucleus 
Explanation: Ans. is 'a' ie Nucleus Parson writes - "It is important to bear in mind that the central nucleus of the lens consists of the oldest cells and the periphery or cortex of the youngest."