The nurse is developing the plan of care for a client with pneumonia and includes the nursing problem of Ineffective airway clearance related to thick pulmonary secretions. Which intervention is most important for the nurse to include in the client's plan of care?

A. Increasing fluid intake helps thin pulmonary secretions, making them easier to expectorate and is most directly related to clearing the airway. B. Providing frequent rest periods is important but does not directly clear the airway. C. Administering O2 addresses hypoxia but does not clear secretions. D. Semi-Fowler's position helps with breathing but does not specifically address thick secretions.