Correct Answer: A

Rationale: Nitroglycerin tablets are light and moisture-sensitive, so they should be stored in a cool, dry place away from light to maintain their effectiveness. Option B advises taking a tablet every 5 minutes, which may lead to overdose. Option C emphasizes the correct administration route for sublingual tablets. Option D is incorrect as water is not needed for the tablets to take effect.

Correct Answer: C

Rationale: When a client with heart failure is prescribed furosemide, the nurse should monitor for hypokalemia. Furosemide is a loop diuretic that can lead to potassium loss, which increases the risk of hypokalemia. Hypokalemia can have serious implications such as cardiac dysrhythmias. Therefore, it is essential to closely monitor the client's serum potassium levels while on furosemide to prevent complications.

Correct Answer: C

Rationale: Nausea is an early sign of theophylline toxicity. The nurse should closely monitor the client for this symptom as it can progress to more severe toxicity. Nausea can be a warning sign to prevent further complications and adjust the dosage as necessary.

Correct Answer: A

Rationale: To monitor the effectiveness of warfarin therapy in a client with atrial fibrillation, the nurse should assess the Prothrombin time (PT) and international normalized ratio (INR) levels. These tests help determine the clotting ability of the blood and ensure that the client's anticoagulation levels are within the therapeutic range, reducing the risk of bleeding or clotting complications.

Correct Answer: A

Rationale: Encouraging the client to cough and deep breathe every 1 to 2 hours is crucial post-CABG surgery to prevent respiratory complications, such as atelectasis and pneumonia. These actions help to expand lung volume, clear secretions, and prevent the collapse of alveoli.