Which of the following is the primary treatment for patent ductus arteriosus (PDA) in a preterm infant?

Correct Answer: B

Rationale: Indomethacin, a nonsteroidal anti-inflammatory drug, is used to help close a patent ductus arteriosus in preterm infants by inhibiting prostaglandins, which are involved in maintaining the ductus open.

Correct Answer: C

Rationale: Bullying involves repeated aggressive behavior by peers, which fits the scenario where the child is being teased. School phobia and anxiety disorders might result from bullying but are secondary conditions. Hypothyroidism is unrelated to this social context.

Correct Answer: A

Rationale: B-Thalassemia results in defective hemoglobin production, leading to microcytosis due to smaller-than-normal red blood cells.

Correct Answer: C

Rationale: Persistent Tic Disorder involves motor or vocal tics that last for more than a year. Tourette's Disorder requires both motor and vocal tics, while Provisional Tic Disorder lasts less than a year. Sydenham Chorea is typically associated with rheumatic fever.

Correct Answer: A

Rationale: The correct answer is A because the closure of the anterior fontanel between ages 12 and 18 months is considered a normal finding in infants. It is a part of the typical growth and development process.