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
Thickest layer of tear film is: 
Select and explain. 
A. Mucus layer, B. Aqueous layer, C. Oily layer, D. None of the above
B: Aqueous layer
Answer: B: Aqueous layer 
Explanation: Ans. Aqueous layer