Correct Answer: A

Rationale: Step 1: Vitamin B12 is absorbed in the small intestine with the help of intrinsic factor produced by parietal cells in the stomach. Step 2: Intrinsic factor binds to vitamin B12, forming a complex that is then absorbed in the ileum. Step 3: If intrinsic factor is lacking (as seen in pernicious anemia), vitamin B12 absorption is impaired, leading to megaloblastic anemia. Step 4: Administering cyanocobalamin bypasses the need for intrinsic factor. Step 5: Thus, intrinsic factor influences Vitamin B12 absorption. Other choices (B, C, D) do not play a direct role in Vitamin B12 absorption.

Correct Answer: D

Rationale: The correct answer is D: Draw up clear insulin first when mixing two types of insulin in one syringe. This is important because mixing insulin requires drawing up the clear (short-acting) insulin first to prevent contamination. This ensures accurate dosing and prevents clouding of the insulin. Drawing up cloudy insulin first can lead to inaccurate dosing and potential mixing errors. Administering insulin after the first meal (choice A) is not the focus of this question. Administering insulin at a 45-degree angle into the deltoid muscle (choice B) is not recommended for insulin injections. Vigorously shaking the vial of insulin before withdrawal (choice C) can cause bubbles and affect the accuracy of the dose.

Correct Answer: D

Rationale: The correct answer is D: Strengthens heart contraction. Digoxin is an inotropic agent that works by increasing the force of the heart's contractions. This leads to improved cardiac output and helps manage conditions like heart failure. Choices A, B, and C are incorrect because digoxin does not decrease heart rate, increase conduction time, or increase heart rate. It specifically targets the strength of the heart's contractions, making option D the most appropriate choice. This action of digoxin is crucial in improving the efficiency of the heart's pumping function.

Correct Answer: B

Rationale: The correct answer is B: Phenytoin (Dilantin). Phenytoin is known to cause gingival hyperplasia as a side effect, which can be minimized with good oral hygiene practices. Procainamide, Azathioprine, and Allopurinol are not associated with gingival hyperplasia. Therefore, the client receiving cyclosporine should focus on practicing good oral hygiene specifically when taking Phenytoin to minimize the risk of developing gingival hyperplasia.

Correct Answer: A

Rationale: The correct answer is A because postural hypotension is defined as a drop in systolic blood pressure of greater than 20 mmHg or a drop in diastolic blood pressure of greater than 10 mmHg within 3 minutes of standing from a sitting or supine position. Therefore, a drop in systolic pressure greater than 10 mmHg when changing from lying to sitting is indicative of postural hypotension. Choice B is incorrect as postural hypotension is primarily defined by changes in systolic blood pressure, not diastolic. Choice C is incorrect because a drop in diastolic pressure greater than 10 mmHg is not the defining characteristic of postural hypotension. Choice D is not provided.