Question

read the passage. then answer the question below.
a cave in mexico was formed as water slowly eroded soft limestone rock. eventually, so much water collected that there is now a river underground.
the underground river environment is home to shrimp, spiders, and crabs that specialize in living in dark environments. in fact, because these animals dont need to see, some dont have any eyes! for example, species such as the mexican blind cavefish survive by eating almost any living thing they bump into, including small insects, crustaceans, and bits of plants that float into the cave.
which of the following best describes an ecosystem in a cave in mexico?
the small insects and the crustaceans
the blind shrimp, the spiders, and the crabs
the mexican blind cave fish, the small insects, and the river

Explanation:

An ecosystem includes both biotic (living organisms) and abiotic (non - living components like water, soil, etc.) elements. The first two options only mention biotic elements (small insects, crustaceans, blind shrimp, spiders, crabs). The third option includes a biotic element (Mexican blind cave fish, small insects) and an abiotic element (the river).

Answer:

the Mexican blind cave fish, the small insects, and the river