Final answer:
Pain relieved by rest is most indicative of a primary cardiac problem, characteristic of stable angina, associated with coronary artery disease.
Step-by-step explanation:
The question asks which symptom is most indicative of a primary cardiac problem. The correct answer is c) Pain relieved by rest. This is a characteristic of stable angina, which is a type of chest pain or discomfort due to coronary artery disease (CAD) that typically occurs with exertion or emotional stress and is relieved by rest or nitroglycerin. Unstable angina, on the other hand, occurs at rest and is more serious as it could indicate an imminent heart attack and requires urgent medical attention.