Correct Answer: B

Rationale: For the management of type 1 diabetes in a child, scheduling frequent blood glucose tests is essential. These tests help in monitoring blood sugar levels, adjusting insulin doses, and ensuring proper glucose control. Choices A, C, and D are incorrect. Providing high-carbohydrate snacks can lead to blood sugar spikes, increasing dietary fat intake is not recommended, and encouraging a high-protein diet is not a standard recommendation for managing type 1 diabetes in children.

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: 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.

Correct Answer: A

Rationale: The correct answer is A: Joint swelling and pain. These are the most common initial symptoms of juvenile idiopathic arthritis, typically affecting multiple joints. Skin rash (choice B), gastrointestinal bleeding (choice C), and neurological deficits (choice D) are not typical initial symptoms of juvenile idiopathic arthritis. Skin rash may be seen in other conditions like dermatitis or systemic lupus erythematosus, gastrointestinal bleeding may be associated with conditions like inflammatory bowel disease, and neurological deficits could be indicative of conditions like multiple sclerosis.

Correct Answer: B

Rationale: The correct answer is B. In a double-blind experiment, neither the subjects nor the researchers know which subjects are in the control or experimental group. This helps to eliminate bias and ensure that the results are more objective. Choice A is incorrect as in a double-blind experiment, subjects do not take turns receiving each treatment; it is about masking the treatment allocation. Choice C is incorrect because it implies that the researchers are aware of the group allocation, which goes against the principle of blinding in a double-blind study. Choice D is incorrect as both subject groups should not know whether they are in the control or experimental group to maintain the blindness of the study.