If two species share identical niches, according to Gause's law, they:
“Cannot coexist” for if two species share identical niches, according to gause's law, they. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Habitat describes where an organism occurs; niche additionally describes how it obtains resources and affects or responds to other organisms. Distribution therefore provides evidence about a niche but is not identical to it. The remaining alternatives—“Coexist peacefully”, “Merge genetically”, “Expand habitats”—refer to different states, processes, or scales a
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 13