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
Soft contact lenses are made of: 
Select and explain. 
A. Polymethyl methacrylate, B. Hydroxymethyl methacrylate, C. Glass, D. Silicone
B: Hydroxymethyl methacrylate
Answer: B: Hydroxymethyl methacrylate 
Explanation: Ans. Hydroxymethyl methacrylate