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
[{'content': 'Tadalafil inhibits \nSelect and explain. \nA. PDE - 3, B. PDE - 4, C. PDE - 5, D. PDE - 6', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Tadalafil & Sildenafil inhibits Phosphodiesterase - 5 (PDE -5) and increase cGMP, They are used in pulmonary hypertension & erectile dysfunction.', 'role': 'assistant'}]