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
Schirmer test measures 
Select and explain. 
A. Basal tear secretion, B. Reflex tear secretion, C. Total tear secretion, D. None of the above
C: Total tear secretion
Answer: C: Total tear secretion 
Explanation: Schirmer test measures total tear production.
Normal value: 15 mm or above/5 minutes.