Consider two cars I and II.
A and D sit in the same car, say I.
H is not in the same car i.e. H is in car II.
B and C are not in the same car in which D is sitting i.e. B and C are in car II.
F sits along with A and E in the same car i.e. car I.
G is in the other car i.e. car II.
Thus, we have :
Car I → A, D, E, F
Car II → B, C, G, H
B and C are sitting in the same car in which G and H are sitting.