Correct Answer: D

Rationale: The correct answer is D. Controls in an experiment ensure that the subjects are similar in all respects except for the treatment being tested. This allows for a fair comparison between the treatment group and the control group. Choice A is incorrect because the size of the groups is not the primary benefit of using controls. Choice B is incorrect as blinding, not controls, refers to subjects not knowing about the experiment. Choice C is incorrect as it pertains more to randomization than the use of controls.

Correct Answer: A

Rationale: When managing a child with an allergy to multiple food items, the most appropriate approach is to avoid all identified allergens. This is crucial to prevent allergic reactions and ensure the child's safety. Choice B, increasing dietary exposure to allergens, is incorrect as it can lead to severe allergic reactions. Choice C, administering daily antihistamines, may help manage symptoms but does not address the root cause, which is avoiding allergens. Choice D, restricting all food intake, is not a viable option as it can lead to malnutrition and other health issues.

Correct Answer: A

Rationale: The correct answer is A: Chest physiotherapy. Treatment for cystic fibrosis focuses on chest physiotherapy and aerosol medications to manage and clear thick pulmonary secretions. Chest physiotherapy helps loosen and clear mucus from the lungs, aiding in breathing and reducing the risk of infections. Mucus-drying agents (choice B) are not typically used in the treatment of cystic fibrosis as the goal is to help clear mucus, not dry it. Prevention of diarrhea (choice C) is not a primary focus in the treatment of cystic fibrosis. Insulin therapy (choice D) is not relevant to cystic fibrosis, which primarily affects the respiratory and digestive systems.

Correct Answer: C

Rationale: Kilojoules are the standard units of energy used by most scientists and nutritionists worldwide. Newtons are units of force, liters are units of volume, and kilocalories are more commonly used in the United States but not as widely adopted internationally for energy measurements. Therefore, the correct answer is 'kilojoules.'

Correct Answer: D

Rationale: Monitoring growth and development is crucial for children with congenital heart disease to ensure they are meeting developmental milestones and managing the disease effectively. This helps healthcare providers assess the child's overall health, detect any potential issues early, and adjust treatment plans accordingly. Restricting physical activity may not be necessary for all children with congenital heart disease and should be determined by their healthcare team based on individual needs. Increasing fluid intake and administering high doses of vitamins may not be directly related to managing congenital heart disease and should be guided by specific recommendations from healthcare providers.