The LPN/LVN Is Reinforcing Instructions to a Client for the Use

The LPN/LVN is reinforcing instructions to a client for the use of an incentive spirometer.Which statement by the client will prompt the LPN/LVN to notify the RN that additional teaching is necessary?

A) "I was able to raise the ball up to the marked level today."
B) "I blow into the mouthpiece 10 times a day just as instructed."
C) "I've been using the incentive spirometer every hour."
D) "I feel so tired when I finish using the incentive spirometer."