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
Orange-skin cornea results due to: 
Select and explain. 
A. Chalcosis, B. Siderosis, C. Ammonia burn, D. Mustard gas
D: Mustard gas
Answer: D: Mustard gas 
Explanation: Ans. Mustard gas