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: Microbiology
Concentration of agar used for solid agar to Inhibit Proteus swarming 
Select and explain. 
A. 1-2%, B. 0.50%, C. 6%, D. 5%
C: 6%
Answer: C: 6% 
Explanation: For solid agar - 1-2%
For Semisolid agar - 0.5%
For solid agar to inhibit proteus swarming - 6%