One of the following drugs may cause pyloric stenosis if administered to a premature infant

Correct Answer: D

Rationale: Dexamethasone has been associated with an increased risk of pyloric stenosis in premature infants. The other drugs are not linked to this condition.

Correct Answer: B

Rationale: The correct answer is B. The best age to introduce solid foods into an infant's diet is typically between 4 to 6 months. At this age, the infant's digestive system has matured enough to handle more complex nutrients, and they have likely lost the extrusion reflex, making swallowing easier. It is an important transition period for introducing new foods.

Correct Answer: C

Rationale: Renal tubular acidosis is associated with normal anion gap metabolic acidosis, unlike conditions like diabetic ketoacidosis and renal failure.

Correct Answer: B

Rationale: Recycling helps reduce pollution by reusing materials and minimizing waste that would otherwise end up in landfills or oceans.

Correct Answer: B

Rationale: Chronic hemolytic anemia patients typically require iron chelation after 8-10 transfusions to prevent iron overload and organ damage.