This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Pharmacology
Which of the following Inhibits theophylline metabolism? 
Select and explain. 
A. INH, B. Griseofulvin, C. Prednisolone, D. Ciprofloxacin
D: Ciprofloxacin
Answer: D: Ciprofloxacin 
Explanation: Plasma concentration of theophylline, warfarin is increased by enzyme inhibitors like ciprofloxacin (also by norfloxacin and pefloxacin) due to inhibition of metabolism: toxicity of these drugs can occur. ESSENTIALS OF MEDICAL PHARMACOLOGY 6TH EDITION KD TRIPATHI Page No:689