Correct Answer: A

Rationale: Hydrocarbon poisons include substances like gasoline, turpentine, and lighter fluid, which are typically liquids derived from petroleum. Bleach is a corrosive substance, not a hydrocarbon.

Correct Answer: A

Rationale: A bone marrow aspirate is the definitive test to confirm acute lymphoblastic leukemia (ALL) in this case. It allows for the examination of leukemic cells in the bone marrow, providing a direct assessment of the disease. Red blood cell count (Choice B) is not specific for diagnosing leukemia but may show anemia commonly seen in leukemia patients. Lumbar puncture (Choice C) is used to assess central nervous system involvement, not primarily for confirming ALL. Bone scan (Choice D) is not a standard diagnostic test for ALL and is mainly used for evaluating bone metastases in other conditions.

Correct Answer: A

Rationale: Hydrocarbon poisons include substances like gasoline, turpentine, and lighter fluid, which are typically liquids derived from petroleum. Bleach is a corrosive substance, not a hydrocarbon.

Correct Answer: C

Rationale: The correct answer is C. Introducing iron-fortified cereal between 4 to 6 months of age is a recommended practice to prevent iron deficiency anemia in infants. Iron-fortified infant cereals are a good source of iron for infants. Choices A and B are incorrect because adding green leafy vegetables to low-iron formula and discontinuing vitamin C supplements do not directly address the prevention of iron deficiency anemia. Choice D is incorrect because cow's milk should be avoided before 12 months of age as it is low in iron and can lead to intestinal blood loss, increasing the risk of iron deficiency anemia.

Correct Answer: A

Rationale: Human milk is preferred, even for preterm infants, because it contains essential nutrients and antibodies that are particularly beneficial for their growth and development. Choice B is incorrect because human milk is rich in essential nutrients necessary for preterm infants. Choice C is incorrect as commercial infant formulas do not provide the same benefits as human milk. Choice D is incorrect as specialized formulas are available to meet the unique nutritional needs of preterm infants, but human milk remains the optimal choice.