This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lens, Subject name: Ophthalmology
Hypovitaminosis - D causes - 
Select and explain. 
A. Zonular cataract, B. Blue - Dot cataract, C. Rosette cataract, D. Cupliform cataract
A: Zonular cataract
Answer: A: Zonular cataract 
Explanation: Zonular or lamellar cataract is a congenital type Etiology may be either genetic or environmental in origin. Environmental form is associated with: deficiencyof vitamin D hypocalcemia Sometimes maternal rubella infection contracted between 7th and 8th week of gestation may also cause lamellar cataract.