This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cataract, Subject name: Ophthalmology
Which of the gene is most often implicated in congenital cataract and alpha crystallin mutation? 
Select and explain. 
A. GLC3A, B. PAX6, C. PITX2, D. CRYAA
D: CRYAA
Answer: D: CRYAA 
Explanation: CRYAA is implicated in congenital cataract and alpha crystallin mutation.