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
Commonest type of cataract is: 
Select and explain. 
A. Blue dot, B. Zonular, C. Cupuliform, D. Cuneiform
A: Blue dot
Answer: A: Blue dot 
Explanation: Ans. Blue dot