Correct Answer: C

Rationale: The correct answer is C: Epinephrine injection. An epinephrine injection is the primary treatment for an anaphylactic reaction in children. Epinephrine acts quickly to reverse severe symptoms such as difficulty breathing, low blood pressure, and hives. Oral antihistamines, although useful for milder allergic reactions, are not sufficient to manage the potentially life-threatening symptoms of anaphylaxis. Intravenous fluids may be necessary to support blood pressure in a child with anaphylaxis but are not the primary treatment. Antipyretics, on the other hand, are medications used to reduce fever and are not indicated as the primary treatment for an anaphylactic reaction.

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: C

Rationale: The correct answer is C: Epinephrine injection. An epinephrine injection is the primary treatment for an anaphylactic reaction in children. Epinephrine acts quickly to reverse severe symptoms such as difficulty breathing, low blood pressure, and hives. Oral antihistamines, although useful for milder allergic reactions, are not sufficient to manage the potentially life-threatening symptoms of anaphylaxis. Intravenous fluids may be necessary to support blood pressure in a child with anaphylaxis but are not the primary treatment. Antipyretics, on the other hand, are medications used to reduce fever and are not indicated as the primary treatment for an anaphylactic reaction.

Correct Answer: C

Rationale: When an increase in exercise is accompanied by a decrease in body weight, it demonstrates a negative correlation. This means that as one variable (exercise) increases, the other variable (body weight) decreases. Choice A, 'variable effect,' is vague and does not accurately describe the relationship between exercise and body weight. Choice B, 'positive correlation,' is incorrect because in a positive correlation, both variables would increase or decrease together. Choice D, 'randomization effect,' is unrelated to the scenario described.

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.