Correct Answer: B

Rationale: A bulging fontanel is a key sign of meningitis in infants, indicating increased intracranial pressure due to inflammation of the meninges. This can lead to the fontanel bulging. Choices A, C, and D are incorrect. Increased appetite is not typically associated with meningitis in infants; instead, they may have poor feeding. A decreased respiratory rate is not a common sign of meningitis in infants. Elevated blood pressure is also not a typical finding in infants with meningitis.

Correct Answer: D

Rationale: The correct answer is D. A placebo serves as a control for comparison with the treatment group, helping to eliminate bias and ensure the results are due to the treatment itself. Placebos are crucial in research to distinguish the actual effect of the treatment from psychological or subjective factors. Choice A is incorrect because the purpose of a placebo is not related to reducing the cost of the experiment. Choice B is incorrect because while placebos are used in double-blind studies, their primary purpose is not to make the experiment double-blind. Choice C is incorrect because the purpose of a placebo is not to increase the number of participants but rather to serve as a comparison group for the treatment being tested.

Correct Answer: B

Rationale: The correct answer is B: Ensure strict infection control measures. Children with acute lymphoblastic leukemia (ALL) who are undergoing chemotherapy have compromised immune systems, making them highly susceptible to infections. Implementing strict infection control measures, such as hand hygiene, limiting exposure to sick individuals, and maintaining a clean environment, is essential to prevent infections. Choice A is incorrect because avoiding all physical activity may not be necessary as long as the child's activity level is appropriate. Choice C is incorrect because increasing daily caloric intake is important to support the child's nutritional needs during treatment. Choice D is incorrect because limiting fluid intake is not typically recommended unless specifically advised by the healthcare provider.

Correct Answer: A

Rationale: When a parent expresses concern about their child's weight gain, the most appropriate response is to provide guidance on healthy eating and physical activity. This approach promotes healthy weight management and overall well-being. Suggesting restrictive dieting (Choice B) can be harmful, especially for children, as it may lead to unhealthy relationships with food and potential nutritional deficiencies. Recommending increased caloric intake (Choice C) without proper assessment and guidance can exacerbate the issue. Avoiding discussing the issue (Choice D) neglects a critical opportunity to address the parent's concerns and support the child's health.

Correct Answer: C

Rationale: During stressful situations like watching an exciting sports match, individuals often seek emotional comfort through food. This emotional connection can lead Farah to choose foods that provide comfort or familiarity rather than being based on regional cuisines (choice A), general preferences (choice B), or positive associations (choice D). Farah's food choice is likely driven by the need for emotional comfort to alleviate her nervousness, making option C the most suitable answer.