A 6-year-old boy with hereditary spherocytosis developed transient aplastic crisis following a recent viral infection. The most probable incriminated viral infection is:

Correct Answer: D

Rationale: Parvovirus B19 infects erythroid progenitor cells, temporarily halting erythropoiesis. In hereditary spherocytosis, this leads to severe anemia, as the lifespan of spherocytes is already reduced.

Correct Answer: B

Rationale: Von Willebrand disease causes prolonged bleeding time despite normal platelet count due to defective platelet adhesion from a deficiency in von Willebrand factor.

Correct Answer: D

Rationale: Tachycardia is an early compensatory response in shock to maintain perfusion before blood pressure drops.

Correct Answer: C

Rationale: Intrauterine growth retardation is uncommon in infants of diabetic mothers

Correct Answer: C

Rationale: Hyperventilation compensates for metabolic acidosis by reducing COâ‚‚, which helps balance pH when bicarbonate is lost.