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
Cataract brunescens results due to deposition of- 
Select and explain. 
A. Urochrome, B. Copper, C. Iron, D. Silver
A: Urochrome
Answer: A: Urochrome 
Explanation: In nuclear senile cataract, there may or may not be assosiated deposition of pigment urochrome and/or melanin derived from amino acids in the lens. commonly observed pigmented nuclear cataracts are amber,brown(cataracta brunescens)or black(cataracta nigra) and rarely reddish(cataracta rubra) in colour. REF IMG