The health care aide notes that Ms. Wood's cough has increased in frequency, and she is experiencing increased shortness of breath and complaining of chills. Which of the following is the most likely explanation for these symptoms?
a. Ms. Wood has developed an infection in her lungs.
b. This is an expected progression of her chronic condition.
c. Ms. Wood has not been taking her cough medication
d. Ms. Wood is not using her oxygen as prescribed