Correct Answer: A

Rationale: Gently tapping over the site helps dilate the veins and increase visibility. Applying a cold compress or raising the extremity above the body level constricts the veins, making them harder to access. Prolonged tourniquet use can cause discomfort and venous congestion.

Correct Answer: C

Rationale: Masturbation in preschool children is a normal behavior as they explore their bodies. It is best viewed as a natural part of development. Parents are often advised to ignore it and provide distractions rather than making the child feel ashamed or embarrassed. Choice A is incorrect because it is a natural behavior and not considered abnormal in this context. Choice B is incorrect as it does not necessarily disrupt the family. Choice D is incorrect as the focus should be on the child's development and well-being, not on the parents' feelings of embarrassment.

Correct Answer: A

Rationale: The correct answer is A: Neuroblastoma. Neuroblastoma, a cancer that arises from nerve tissue, is associated with increased levels of catecholamine metabolites, including VMA and HVA, in the urine. Nephroblastoma (Wilms tumor) is a type of kidney cancer and is not typically associated with elevated levels of catecholamine breakdown products. Leukemia is a cancer of the blood and bone marrow and does not lead to increased VMA and HVA excretion in urine. Osteosarcoma is a bone cancer and is not linked to elevated levels of catecholamine metabolites in the urine.

Correct Answer: A

Rationale: The correct answer is A. A child is expected to double their birth weight by 6 months. This is a common guideline used to monitor healthy growth and development in infants. Choices B, C, and D are incorrect as they do not provide the expected weight based on the given information.

Correct Answer: B

Rationale: Mixing activated charcoal with a flavorful beverage in an opaque container can help mask the taste and encourage the child to ingest it. Using an opaque container can prevent the child from seeing the unappealing appearance of the charcoal mixture, increasing compliance.