Correct Answer: A

Rationale: The correct answer is A: 'Avoid crossing your legs at the knees or ankles.' Crossing legs at the knees or ankles can cause excessive stress on the new hip joint, leading to a risk of dislocation. Choice B is incorrect because sleeping on the side of the operated hip can also increase the risk of dislocation. Choice C is incorrect as sitting in low chairs with knees higher than hips is a recommended position to prevent hip dislocation. Choice D is incorrect because bending forward at the waist to pick up objects can strain the hip joint and increase the risk of dislocation.

Correct Answer: A

Rationale: The correct answer is Vitamin A. Vitamin A deficiency leads to night blindness because this vitamin is crucial for the formation of rhodopsin, a photopigment in the retina. Rhodopsin is essential for vision in low-light conditions. Vitamin B12 deficiency can lead to anemia and neurological issues but is not directly related to night blindness. Vitamin C deficiency can cause scurvy, affecting connective tissues, but not night vision. Vitamin D deficiency can lead to bone disorders but is not primarily associated with night blindness.

Correct Answer: A

Rationale: The correct response is A: 'Do not expose other children as the virus is very contagious even without direct contact.' RSV is highly contagious, especially in young children. Allowing the infected child to attend a birthday party can put other children at risk of contracting the virus. Choice B is incorrect as RSV can remain contagious for a period of time. Choice C is not sufficient, as wearing a mask may not entirely prevent the spread of the virus. Choice D is inaccurate, as children under 5 months are not the only ones susceptible to RSV; all young children are at risk.

Correct Answer: C

Rationale: A low sodium, low potassium diet is often recommended for patients with CKD to manage fluid balance and prevent electrolyte imbalances that the kidneys can no longer regulate effectively. High protein diets, as mentioned in choice A, can put extra strain on the kidneys, making it an incorrect choice. Choice B, which suggests a low protein, high potassium diet, is also incorrect because high potassium levels can be harmful to individuals with CKD. Choice D, advocating for a high calcium, low phosphorus diet, is not the typical dietary recommendation for CKD patients, even though managing calcium and phosphorus levels is important in their diet.

Correct Answer: A

Rationale: The correct answer is A: Oxygen transport. Hemoglobin in red blood cells binds to oxygen in the lungs and carries it to tissues throughout the body, releasing it where needed. This process is essential for cellular respiration and energy production. Choices B, C, and D are incorrect because hemoglobin's primary function is not related to immunity, blood clotting, or carbon dioxide transport. Hemoglobin's main role is to transport oxygen, ensuring adequate oxygen supply to body tissues for metabolic processes.