A 5-day-old term baby is brought in with jaundice. He is breastfed, otherwise well, feeding adequately and afebrile. Jaundice extends to the legs. There is no haemolysis on blood tests. What is the most appropriate next step?AReassure and arrange review at 2 weeks onlyBStart phototherapy urgently without any further testsCMeasure total serum bilirubin and plot on the newborn bilirubin nomogramDStart exchange transfusionEStop breastfeeding immediatelyCheck my answer