You are answering a USMLE-style medical question. Question: A one-week-old, full-term infant born by uncomplicated vaginal delivery is brought to a pediatrician by his mother, who notes that her daughter's skin appears yellow. She reports that the child cries several times per day and sleeps 7-8 hours at night, uninterrupted. She has been breastfeeding exclusively and feels that he has been feeding well. Which of the following is the best treatment for this condition? Options: A) Phenobarbital administration B) Plasma exchange C) Switch from breast milk to formula D) Continue normal breast feeding Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.