## **Core Concept**
The question assesses the understanding of neonatal jaundice, specifically the correlation between the extent of icterus (jaundice) and bilirubin levels in newborns. Icterus involving the soles in a newborn is a significant indicator of high bilirubin levels, suggesting severe jaundice.

## **Why the Correct Answer is Right**
In newborns, the extent of jaundice can be assessed by its distribution on the body, which correlates with bilirubin levels. Icterus extending to the soles is generally associated with very high bilirubin levels, typically above 20 mg/dl. This is because bilirubin levels can be estimated based on the zone of icterus:
- Face and neck: 5-8 mg/dl
- Trunk: 10-12 mg/dl
- Lower trunk and thighs: 15-18 mg/dl
- Sole: >20 mg/dl

## **Why Each Wrong Option is Incorrect**
- **Option A:** 20 mg/dl)

## **Correct Answer:** . >20.