Correct Answer: B

Rationale: The correct answer is B: Hemophilia is an X-linked recessive disorder, primarily affecting males and passed from mothers to sons. It involves a deficiency in clotting factors, leading to prolonged bleeding. Choice A is incorrect as hemophilia is not autosomal dominant. Choice C is incorrect as hemophilia does not involve platelets. Choice D is incorrect as hemophilia is not autosomal recessive.

Correct Answer: A

Rationale: In the case of severe isotonic dehydration, the initial fluid of choice is 0.9% normal saline. This solution is preferred because it helps to restore both fluids and electrolytes effectively. Options B, C, and D are not suitable for the initial management of severe isotonic dehydration. D5 0.2% (1/4) normal saline (Choice B) is a hypotonic solution and might worsen the imbalance. D5W (Choice C) is a hypotonic solution that does not contain electrolytes essential for rehydration. Albumin (Choice D) is a colloid solution used for specific indications like hypoproteinemia or hypoalbuminemia, not for initial rehydration in severe dehydration.

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: C

Rationale: Giardia lamblia is a protozoan parasite known to cause acute diarrhea, often through contaminated water or food. Shigella, Salmonella, and E. coli are bacterial pathogens that also cause diarrhea but are not parasites.

Correct Answer: B

Rationale: The correct answer is B: Hemophilia is an X-linked recessive disorder, primarily affecting males and passed from mothers to sons. It involves a deficiency in clotting factors, leading to prolonged bleeding. Choice A is incorrect as hemophilia is not autosomal dominant. Choice C is incorrect as hemophilia does not involve platelets. Choice D is incorrect as hemophilia is not autosomal recessive.