A person with asthma may carry an inhaler for helping when they have an asthma attack and have difficulty breathing. Some inhalers contain a bronchodilator that relaxes the smooth muscle of the airways to cause bronchodllation. This means that the bronchodllator medicine in this type of inhaler is most influential on what part of the bronchial tree?
A. The trachea
B. The carina
C. The bronchioles
