The Nurse Instructs the Patient with Chronic Obstructive Pulmonary Disease

The nurse instructs the patient with chronic obstructive pulmonary disease (COPD) on methods to lower the risk of lung complications. One technique is the "long huff" cough. What is the rationale for this type of coughing exercise?

A) Increases oxygenation
B) Removes excess carbon dioxide
C) Ensures thorough lung expansion
D) Helps to open and clear smaller airways