50% direct bilirubin means conjugated hyperbilirubinemia. Normally the direct (conjugated) bilirubin is less than 15-20% of total bilirubin.Normal Values of bilirubin Total bilirubin       >             0.2 - 1.9 mg/d1.     Direct bilirubin >             0 - 0.3 mg/dl.So, this child has : -Conjugated hyperbilirubinemia Other LFTs normalAmongst the given options, Rotor syndrome and Primary biliary cirrhosis cause conjugated hyperbilirubinemia. In Primary biliary cirrhosis, other LFTs are also abnormal, e.g., SGOT and SGPT are raised. Now we are left with Rotor syndrome which causes conjugated hyperbilirubinemia. Other LFTs are normal.