A strongly connected component of a digraph is defined as the maximal set of vertices in which there is a path from any one vertex to any other vertex in the set.

In this example ( link : http://lcm.csa.iisc.ernet.in/dsa/img386.gif ): I can't see why (C), (A, B, C) are the strong components of G rather than (A, B, C, D). (We can see that in (A, B, C, D), there is always a path from any one vertex to any other)

Any clue ?