Correct Answer: C

Rationale: A decrease in hemoglobin A1C is a more specific indicator of metformin's effectiveness in controlling blood glucose levels over a longer period compared to fasting blood glucose levels. Hemoglobin A1C reflects average blood sugar levels over the past 2-3 months, providing a more comprehensive view of glycemic control.

Correct Answer: B

Rationale: The correct instruction for a client prescribed an anticoagulant for atrial fibrillation is to avoid activities that may cause injury. Anticoagulants increase the risk of bleeding, so it is important to prevent situations that could lead to injury or trauma.

Correct Answer: A

Rationale: Correct. Aluminum hydroxide is known to cause constipation as a common side effect. Instructing the client about this potential adverse effect is important for their awareness and management. Monitoring and managing constipation can help improve the client's comfort and overall treatment experience.

Correct Answer: A

Rationale: A severe adverse effect of warfarin is bleeding. Warfarin is an anticoagulant medication that works by inhibiting blood clotting factors, which can lead to an increased risk of bleeding. Excessive bleeding can occur internally or externally, and it is crucial for individuals taking warfarin to be aware of this potential complication and seek medical attention if they experience any signs of bleeding.

Correct Answer: C

Rationale: Enoxaparin is administered subcutaneously, typically in the abdomen to ensure proper absorption. Massaging the injection site should be avoided to prevent bruising or bleeding under the skin.