Early in the Morning, a Male Patient Sees His Physician

Early in the morning, a male patient sees his physician because he and his wife have been trying to start a family. According to the patient, his wife was told that she is able to become pregnant, and he wants to have the physician check him for sterility. The physician notices that the patient has a heavy cough. Upon questioning, the patient reveals that he also coughs in the evening, produces a lot of sputum, and has had numerous colds and even occasional pneumonia. The doctor asks for a sperm sample but already is thinking of a possible diagnosis of Kartagener's syndrome, a genetic disorder that affects

A) a number of keratins
B) microtubule-associated proteins
C) thick filaments.
D) thin filaments
E) intermediate filaments