Answer:
d. Natural selection eliminated the other bacteria in the pond ecosystem.
Explanation:
Natural selection is a type of selection in which nature selects the most suited species or organisms for a particular environment. In this pond environment, only nylon eating bacteria survive due to the availability of food in the form of nylon while all other bacteria die due to the unavailability of food or they are unable to consume nylon in the pond. So that's why nylon eating bacteria survived and other bacteria removed from the pond.