The Nurse Is Explaining the Difference Between Exertional Angina and Unstable

The nurse is explaining the difference between exertional angina and unstable angina.Which statement about unstable angina is accurate?

A) Unstable angina occurs with moderate exercise.
B) Unstable angina occurs when the blood pressure increases sharply.
C) Unstable angina occurs when the body reacts to high stress levels.
D) Unstable angina occurs unpredictably, even in sleep.