Threshold-based reasoning: For a healthy term newborn, phototherapy is usually started when total serum bilirubin is roughly 15 mg/dL or higher (read off the age-in-hours nomogram), and exchange transfusion only at much higher, dangerous levels. Here the value is 14 mg/dL.
Working through the options: Exchange transfusion (option a) is a last-resort move for severe hyperbilirubinemia threatening kernicterus, nowhere near 14 mg/dL. Phototherapy (option c) has not yet crossed its threshold in a well term baby. Stopping feeds is not advised because breast milk supply must be maintained and good feeding actually helps clear bilirubin.
Bottom line: Keep the baby on the breast and increase feed frequency to more than 10 times a day. So continue to breastfeed is the correct answer.