A client asks the nurse to explain the difference between stable and unstable angina. What is the best response by the nurse?

C Stable angina is caused by spasms of the coronary arteries. Unstable angina is when angina episodes become more frequent or severe, and occur during periods of rest. B Unstable angina is predictable in its frequency, intensity, and duration. Stable angina is when angina episodes become more frequent or severe, and occur during periods of rest. D Unstable angina is caused by spasms of the coronary arteries. Stable angina is when angina episodes become more frequent or severe, and occur during period of rest. A Stable angina is predictable in its frequency, intensity, and duration. Unstable angina is when angina episodes become more frequent or severe, and occur during periods of rest.