This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
A term baby developed jaundice on 3rd day upto the thigh with normal stool and urine. Mother's blood group is 'O' -ve and that of babies 'A' +ve. The cause of jaundice is - 
Select and explain. 
A. Rh incompatibility, B. Physiological jaundice, C. Extrahepatic biliary atresia, D. Sepsis
B: Physiological jaundice
Answer: B: Physiological jaundice 
Explanation: Ans. is 'b' i.e., Physiological jaundice Physiological jaundice o Most neonates develop visible jaundice due to elevation of unconjugated bilirubin concentration during their first week. o This common condition is called physiological jaundice. o This pattern of hyperbilirubinemia has been classified into two functionally distinct periods ? 1. Phase one Last for 5 days in term infant with peak bilirubin levels to 12 mg/dl. Last for 7 days in preterm infant with peak bilirubin levels to 15 mg/dl. 2. Phase two There is decline to about 2 mg/dl, which lasts for 2 weeks after which adult values are attained.