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: Pharmacology
In cotrimoxazole, sulphamethoxazole and trimethoprim are in ratio of: 
Select and explain. 
A. 2:01, B. 1:01, C. 5:01, D. 4:05
C: 5:01
Answer: C: 5:01 
Explanation: 5:01