While Teaching a Patient with Asthma the Appropriate Use of a Peak

While teaching a patient with asthma the appropriate use of a peak flow meter,the nurse instructs the patient to implement which of the following actions?

A) Take and record peak flow readings when having asthma symptoms or an attack.
B) Increase the doses of long-term control medications if the peak flow numbers decrease.
C) Use the flow meter each morning after taking medications to evaluate the effectiveness of the medications.
D) Empty the lungs,and then inhale as rapidly as possible through the mouthpiece to measure how fast air can be inhaled.