I'm working on this problem, but I'm not sure I've done it correctly. My initial thought was that the answer was $D$, but I don't see anything in the above graph that indicated the Hybrid species is,in fact, less fit for survival. Moreover, I cannot see why any of $A,B,C$ would need hold.
The number of off springs produced by the Generation 0 and 4 is almost the same in case of Hybrids. This indicates that the rate of production in the Hybrids is almost the same among different generations.In this case option D will be the best one to choose.