Head banging, hair twirling, rocking, thumb sucking, teeth grinding, and nail biting all are

Correct Answer: A

Rationale: These behaviors are classified as habit disorders, which often serve as self-soothing mechanisms to relieve tension or anxiety. They are not necessarily indicative of poor parenting or tics.

Correct Answer: B

Rationale: Large VSDs typically present with symptoms like heart failure and failure to thrive within 1-3 months of age.

Correct Answer: A

Rationale: Hereditary spherocytosis causes normocytic anemia due to membrane defects, not microcytosis. Microcytic hypochromic anemia results from reduced hemoglobin synthesis, as seen in thalassemia and iron deficiency anemia.

Correct Answer: D

Rationale: Shellfish allergy is often lifelong, unlike milk or egg allergies, which many children outgrow.

Correct Answer: C

Rationale: Biliary atresia accounts for about 25% of neonatal cholestasis cases, leading to bile duct obstruction and liver damage.