A 45-Year-Old Man Is in the Clinic for "A Routine

A 45-year-old man is in the clinic for "a routine physical." During history-taking,the patient states he has been having difficulty sleeping."I'll be sleeping great,and then I wake up and feel like I can't get my breath." The nurse's best response to this would be:

A) "When was your last electrocardiogram?"
B) "It's probably because it's been so hot at night."
C) "Do you have any history of problems with your heart?"
D) "Have you had a recent sinus infection or upper respiratory infection?"