This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Special Senses, Subject name: Physiology
Aqueous humor has lower concentration of: 
Select and explain. 
A. Lactate, B. Protein, C. Hyaluronic acid, D. L-ascorbic acid
B: Protein
Answer: B: Protein 
Explanation: Protein content of aqueous humor is much less than that of plasma. The ocular tissue surrounding the aqueous humor (especially the cornea and lens) take up glucose from aqueous humor; glycolysis by these tissues results in higher pyruvate and lactate (and lower glucose) in aqueous humor. L-ascorbic acid content of aqueous humor is 10-50 times higher as compared to plasma. (However, no ocular defects have been noted in prolonged scurvy.) The aqueous humor contains moderately high amounts of hyaluronic acid; it is kept in the depolymerized state by hyaluronidase present in the ciliary body