Correct Answer: C

Rationale: Bibasilar crackles are abnormal lung sounds that indicate fluid accumulation in the lungs, a sign that left-sided heart failure is worsening. This finding suggests that the client's condition is deteriorating and requires prompt intervention to prevent further complications.

Correct Answer: B

Rationale: Atrial fibrillation is characterized by an irregular and often rapid heart rate, which can lead to poor blood flow due to ineffective contractions of the atria.

Correct Answer: A

Rationale: When using a metered-dose inhaler, the client should take a deep breath and then exhale just before administration. This technique helps ensure that the medication is inhaled effectively. By exhaling before administration, the client can fully inhale the medication into the lungs, maximizing its therapeutic effects.

Correct Answer: D

Rationale: Lemonade is the correct choice as it is caffeine-free, unlike tea, cola, and coffee, which contain caffeine that can potentially affect the client's heart rhythm. Caffeine can increase heart rate and blood pressure, which may not be advisable for a client with a recent MI.

Correct Answer: A

Rationale: In hyperkalemia, tall, peaked T waves are a distinct ECG finding. These T waves can be seen as a result of increased serum potassium levels, affecting the repolarization phase of the cardiac action potential. It is crucial for healthcare providers to recognize this ECG change promptly as hyperkalemia can lead to serious cardiac arrhythmias and complications.