Which of the Following Explains the Lack of Response to Bronchodilators

Multiple Choice

Which of the following explains the lack of response to bronchodilators by some patients with severe emphysema?

A) Airway obstruction is caused by severe bronchospasm.
B) Airway obstruction is caused by passive airway compression and collapse during expiration.
C) Airway obstruction is associated with air trapping.
D) Airway obstruction with hyperinflation is not sensitive to bronchodilators.