An 18-month-old child is brought to the emergency department with suspected croup. The child appears frightened and cries as the nurse approaches him. The nurse needs to assess the child’s breath sounds. The best way to approach the child is to（）
A. expose the child’s chest quickly and auscultate breath sounds as quickly and efficiently as possible.
B. ask the mother to wait briefly outside until the assessment is over.
C. tell the child the nurse is going to listen to his chest with the stethoscope.
D. allow the child to handle the stethoscope before listening to his lungs.