This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Liver & Biliary Tract, Subject name: Pathology
The following features differentiate Rotor syndrome from Dubin Johnson's syndrome EXCEPT 
Select and explain. 
A. Liver in patients with Rotor syndrome has no increased pigmentation and appears normal, B. In Rotor syndrome, Gall bladder is usually visualized on cholecystography, C. Total urinary coproporphyin is substantially increased in Rotor syndrome, D. Fraction of coproporphyin I in urine is elevated usually more than 80% of the total in Rotor syndrome
D: Fraction of coproporphyin I in urine is elevated usually more than 80% of the total in Rotor syndrome
Answer: D: Fraction of coproporphyin I in urine is elevated usually more than 80% of the total in Rotor syndrome 
Explanation: Ans. (d) Fraction of coproporphyrin I in urine is elevated usually more than 80% of the total in Rotor syndrome(Ref: Harrison 18th/Chapter 303)Differentiation between Dubin-Johnson syndrome & Rotor syndrome:CharacteristicDubin-Johnson syndromeRotor syndromePigmentation of LiverPigmented cytoplasmic globulesNot seen; normal histologyTotal urinary coproporphyrin excretionNormalIncreasedFraction of coproporphyrin I/III in urine>80% of total Q<70% of the total QBSP clearanceNormal Q with refluxDelayed Q No reflux