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: Dental
All the strains of A.A. Comitans are sensitive to: 
Select and explain. 
A. Tetracycline, B. Ciprofloxacin, C. Augmenting, D. Metronidazole
B: Ciprofloxacin
Answer: B: Ciprofloxacin 
Explanation: If given :Ciprofloxacin+ metronidazole is the best option.