A 14-day-old neonate presents with convulsions and rapid breathing. On exam, he also has jaundice. What is the most likely underlying cause?

Correct option is C

In a 14-day-old, convulsions + fast breathing + jaundice = late-onset neonatal sepsis with CNS involvement. Physiological or breast milk jaundice rarely cause seizures.
Explanation of options: (a) ✘ Physiological jaundice peaks day 3–5, resolves <10 days, no seizures. (b) ✘ Breast milk jaundice is benign, does not cause convulsions. (c) ✔ Correct; neonatal sepsis often presents with convulsions, tachypnea, jaundice. (d) ✘ Kernicterus causes lethargy, hypotonia, not fast breathing + sepsis features.