2 points
During natural selection, some organisms will survive & reproduce better
than others. This is due to
Random Chance
Humans choosing which animals to breed
Environmental pressures resulting in organisms with certain traits having the best
reproductive success
O
Luck

Environmental pressures resulting in organisms with certain traits having the best

reproductive success

Explanation:

its natural selection and survival of the fittest

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

condensation. good luck!