DIRECTIONS: Study the following information to answer the given questions. 

There are 8 friends A, B, C, D, E, F, G and H seated in a circle facing the cent re. AC, DG, HE and FB are seated adjacent to each other. A is also seated adjacent to H. B is 2nd to the right of H. E is 3rd to the
right of C.

Who amongst the following pairs may not be seated adjacent to each other?

Given:

There are 8 friends A, B, C, D, E, F, G and H seated in a circle facing the cent re. AC, DG, HE and FB are seated adjacent to each other. A is also seated adjacent to H. B is 2nd to the right of H. E is 3rd to the
right of C.

Solutions:

A is also seated adjacent to H.

 B is 2nd to the right of H.

 E is 3rd to the right of C.

AC, DG, HE and FB are seated adjacent to each other. 

Final arrangement.

From the above arrangements, the positions of D and G is not clear, so, from the options, if D is placed near to F, then DC cannot be together, but if position of G is near to F then DC can be together, thus, it cannot be determined.

Hence, the answer Cannot be determined.