Correct Answer: B

Rationale: Providing frequent oral care is crucial when a client is NPO to ensure comfort and prevent drying of the oral mucosa. In this situation, the priority is maintaining oral hygiene to prevent complications such as oral mucosa breakdown. Monitoring bowel sounds may be important in assessing bowel activity, but it is not the priority when the client is NPO due to a small bowel obstruction. Encouraging ambulation can be beneficial for other conditions, but in this case, oral care takes precedence. Measuring abdominal girth is more relevant for assessing abdominal distention, which is not the priority when the client is NPO. Therefore, the most important nursing intervention is to provide frequent oral care.

Correct Answer: D

Rationale: The correct answer is D, Peritoneum. The peritoneum is the membrane that lines the abdominal cavity, providing support to abdominal organs and serving as a conduit for their blood vessels. Choices A, B, and C are incorrect. The perineum refers to the area between the anus and the external genitalia, the pericardium is the membrane enclosing the heart, and the pleura is the membrane surrounding the lungs.

Correct Answer: B

Rationale: The correct initial intervention for a client with chronic heart failure presenting with dyspnea and fatigue is oxygen therapy. Oxygen therapy can help relieve dyspnea and improve oxygen saturation levels, which are crucial in managing heart failure exacerbations. Administering IV diuretics may be necessary later to address fluid overload, but oxygen therapy takes precedence in addressing the immediate respiratory distress. Bed rest and dietary consultation are important aspects of care for heart failure patients, but in this scenario, oxygen therapy is the priority to improve the client's respiratory status.

Correct Answer: C

Rationale: The correct angle of insertion for a subcutaneous injection, such as heparin, is 45 degrees. This angle is appropriate as it helps to ensure proper delivery of the medication into the subcutaneous tissue. Option A (15 degrees) is too shallow for a subcutaneous injection and may result in the medication being deposited into the muscle. Option B (30 degrees) is also too shallow for subcutaneous injections. Option D (90 degrees) is used for intramuscular injections, not subcutaneous injections.

Correct Answer: B

Rationale: The correct answer is B: Reduces gastric acid production. Omeprazole is a proton pump inhibitor that works by reducing gastric acid production, thereby helping to heal ulcers. While neutralizing stomach acid is associated with antacids, forming a protective barrier over ulcers is more characteristic of medications like sucralfate. The action described in choice D, increasing gastric mucus production, is not the primary mechanism of action of omeprazole in treating peptic ulcer disease.