A 68-Year-Old Patient Is Admitted to the Critical Care Unit

A 68-year-old patient is admitted to the critical care unit with reports of midchest pressure radiating into the jaw and shortness of breath when walking up stairs.The patient is admitted with a diagnosis of "rule out myocardial infarction." When inspecting the patient, the nurse notes that the patient needs to sit in a high Fowler position to breathe.This may indicate

A) pericarditis.
B) anxiety.
C) heart failure.
D) angina.