Can someone help me I legit don’t understand this

Groups of organisms with low biotic potential, such as gray whales, that produce at most one offspring every other year a) are r-selected b) are k-selected c) are not subject to density-dependent limiting factors d) show the initial stages of the extinction process e) have escaped from the processes of natural selection and adaptation

Which events are likely to be catastrophic to an ecosystem? select the three correct answers.a-hurricane.b-steady population growth.c-seasonal flooding.d-introducing of an aggressive invasive species.e-tsunami.

Researchers want to use edna to look for an invasive species in the water which of the steps would be likely do last