Please Read the Clinical Scenario, and Then Answer the Question

Multiple Choice

Please read the clinical scenario, and then answer the question that follow to become familiar with the traditional NCLEX question format.
JV is a 16-year-old male with cystic fibrosis. He has been admitted several times to your pulmonary inpatient unit with multiple microorganism infections, including Pseudomonas and H. influenza. Because of the thickness of his mucous secretions, his cilia become immobile and unable to clear his lungs of bacteria harboring mucus. He is supposed to perform vigorous airway mucous clearance at home with a vibrating vest and IPV (intrapulmonary percussive ventilation) device. However, he says that it takes hours and he does not always feel sick. Therefore, he often refuses to do his therapies at home.
-JV asks you to explain what cilia are to him.All of the following are correct answers except

A) they form a microscopic brushlike lining.
B) they help move and expel foreign invaders.
C) they compose a sort of ciliary "escalator."
D) they are chemical-excreting fighter cells.