**Core Concept**
The question involves a neonate presenting with hypoglycemia and jaundice, suggesting a metabolic disorder. The underlying principle being tested is the ability to diagnose and manage metabolic disorders in neonates, specifically those affecting glucose metabolism and bilirubin levels.

**Why the Correct Answer is Right**
Given the symptoms of hypoglycemia and jaundice in a neonate, the most likely diagnosis is a metabolic disorder affecting glucose production or utilization, and bilirubin metabolism. One such condition is **galactosemia**, where the inability to metabolize galactose leads to accumulation of toxic metabolites, causing liver dysfunction, which in turn leads to hypoglycemia and jaundice.

**Why Each Wrong Option is Incorrect**
**Option A:** Would be incorrect as it doesn't directly relate to the symptoms provided.
**Option B:** Similarly, would not directly cause both hypoglycemia and jaundice as primary symptoms.
**Option C:** Might be considered but is less likely given the specific combination of symptoms.
**Option D:** Is not typically associated with both hypoglycemia and jaundice in the neonatal period.

**Clinical Pearl / High-Yield Fact**
Neonates presenting with hypoglycemia and jaundice should prompt an investigation into metabolic disorders. **Galactosemia** is a classic example where early diagnosis is crucial to prevent long-term complications.

**Correct Answer:** D. Galactosemia