Four of the following five are alike in a certain way and hence form a group. Who among the following person does not belong to that group?

A sits second to the left of G, who sits at one of the corner of the table. H sits either to the immediate right or to the immediate left of A. From the above condition, there are two possibilities. D sits opposite to the one who sits second to the left of C. C sits in the middle of the sides of table. D is neither the immediate neighbor of G nor A E is the immediate neighbor of either of A or F, but not the both. B sits second to the left of F. From the above condition, case1 gets eliminated.   Case 2 shows the final arrangement.