单选题 The nurse is evaluating a client who is complaining of shortness of breath. The client's respiratory rate is 26 breaths per minute so the nurse documents that he is tachypneic. The nurse understands that tachypnea means
A. frequent bowel sounds.
B. heart rate greater than 100 beats/minute
C. hyperventilation.
D. respiratory rate greater than 20 breaths/minute