Correct Answer: B

Rationale: A serum calcium level below normal (hypocalcemia) can lead to cardiac arrhythmias and potentially cardiac arrest. Calcium plays a crucial role in cardiac muscle contractility, and low levels can disrupt normal heart function, potentially leading to fatal arrhythmias and cardiac arrest.

Correct Answer: C

Rationale: Assessing the apical pulse is crucial before administering digoxin because the medication can lead to bradycardia. Monitoring the apical pulse helps determine the heart rate, and digoxin is typically withheld if the pulse is below 60 beats per minute. This assessment is essential to prevent potential adverse effects associated with digoxin administration.

Correct Answer: A

Rationale: Protamine sulfate is the antidote for heparin, used to reverse its anticoagulant effects. It should be readily available in case of bleeding complications, as it can rapidly neutralize the effects of heparin and prevent excessive bleeding.

Correct Answer: C

Rationale: The therapeutic response by the nurse in this situation involves reflecting the client's feelings back to them, which demonstrates active listening and empathy. By restating the client's preference to talk to their doctor, the nurse acknowledges and validates the client's feelings, thereby fostering a positive therapeutic relationship and promoting open communication.

Correct Answer: A

Rationale: Choice A is the correct answer because regular physical activity, like walking for half an hour daily, is beneficial for managing coronary artery disease (CAD) and promoting heart health. It helps improve circulation, reduce cholesterol levels, and maintain a healthy weight, which are all important factors in managing CAD. Choices B, C, and D are incorrect as they convey misconceptions about disease management for CAD.