No one but the experts was able to realize that the painting was an imitation. It greatly resembled the original.  

A  It was hard for ordinary people to judge between the fake painting and the real one, but not for the experts.  

B It was obvious that only a person with great talent could fake a painting so successfully.   

C It was almost impossible for amateurs to realize that the painting was not authentic, though the experts could judge it quite easily.   

D  The painting looked so much like the authentic one that only the experts could tell it wasn't genuine.