## Core Concept
The question tests knowledge on vitamin deficiencies causing specific neurological symptoms in neonates. **Vitamin B6 (pyridoxine)** plays a crucial role in the synthesis of neurotransmitters and myelin in the nervous system. Its deficiency can lead to neurological manifestations.

## Why the Correct Answer is Right
The correct answer, **Vitamin B6**, is linked to neonatal seizures due to its critical role in brain function and development. Pyridoxine is a cofactor for many enzymes involved in neurotransmitter synthesis, including serotonin, dopamine, and GABA. A deficiency in Vitamin B6 can lead to a form of epilepsy known as **pyridoxine-dependent epilepsy**, which often presents with seizures in the neonatal period.

## Why Each Wrong Option is Incorrect
- **Option A:** Vitamin A deficiency primarily causes issues related to vision, immune function, and skin integrity, not typically neonatal seizures.
- **Option B:** While Vitamin D deficiency has been associated with various health issues, including muscle weakness and increased risk of infections, it is not directly linked to neonatal seizures.
- **Option D:** Vitamin E deficiency can lead to neurological problems due to its role as an antioxidant, but it is less commonly associated with neonatal seizures compared to Vitamin B6.

## Clinical Pearl / High-Yield Fact
A key clinical pearl is that **pyridoxine-dependent epilepsy** is a condition where seizures are resistant to conventional antiepileptic drugs but responsive to Vitamin B6 supplementation. Early diagnosis and treatment can significantly improve outcomes.

## Correct Answer Line
**Correct Answer: C. Vitamin B6.**