In a salt marsh, a fish eats decaying material from around the base of Spartina grass plants. A snail scrapes algae from the stalks of the Spartina grass. These species can coexist in the same area because they have:

a. The same niche, but different habitats.
b. The same habitat and the same niche.
c. The same habitat, but different niches.
d. Different habitats and different niches.