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
The inhalational bronchodilator with long duration of action is: 
Select and explain. 
A. Salbutamol, B. Theophylline, C. Ipratropium bromide, D. Tiotropium bromide
D: Tiotropium bromide
Answer: D: Tiotropium bromide 
Explanation: Tiotropium bromide :
A newer congener of ipratropium bromide which binds very tightly to bronchial M1 / M3 muscarinic receptors producing long lasting bronchodilatation.
Reference: Essentials of Medical Pharmacology Eighth Edition KD TRIPATHI page no 128