Correct Answer: B

Rationale: Encouraging frequent urination is a key preventive measure for avoiding urinary tract infections (UTIs) in children. It helps flush bacteria from the urinary tract, reducing the risk of UTIs. Restricting fluid intake (Choice A) is not recommended as it may lead to concentrated urine and increase the risk of UTIs. Using topical antibiotics (Choice C) is not a preventive measure for UTIs and should only be used under medical guidance. Increasing dietary calcium (Choice D) is not directly linked to preventing UTIs in children.

Correct Answer: C

Rationale: The correct answer is C. Most foods contain a mixture of the three energy nutrients (carbohydrates, proteins, fats), with one or two predominating. Choice A is correct because most foods do contain a combination of energy nutrients, with one or two types usually being predominant. Choice B is incorrect as foods typically do not contain equal amounts of carbohydrates, proteins, and fats. Choice D is incorrect because most foods contain all three energy nutrients, not just one or two types.

Correct Answer: B

Rationale: A gluten-free diet is crucial for managing celiac disease in children because it helps prevent intestinal damage and alleviate symptoms. Gluten is a protein found in wheat, barley, and rye, and it triggers an immune response in individuals with celiac disease, damaging the lining of the small intestine. Therefore, choices A, C, and D are incorrect. While iron intake is important for overall health, a child with celiac disease can still meet their iron needs through sources that are naturally gluten-free or fortified. A high-protein diet or a low-sodium diet are not specifically required for managing celiac disease.

Correct Answer: D

Rationale: The correct answer is D: 13. There are 13 essential vitamins required in the diet of human beings, including vitamins A, C, D, E, K, and the B vitamins. Choice A (5), Choice B (8), and Choice C (10) are incorrect because they do not represent the total number of essential vitamins needed by human beings.

Correct Answer: D

Rationale: In a child with hemophilia, the lab result that should be abnormal is the partial thromboplastin time (PTT). Hemophilia is a disorder that affects the clotting factors in the intrinsic pathway of coagulation, leading to a prolonged PTT. Prothrombin time (Choice A) assesses the extrinsic pathway and should be normal in hemophilia. Bleeding time (Choice B) evaluates platelet function, which is typically normal in hemophilia. Platelet count (Choice C) measures the number of platelets and is not directly affected by hemophilia.