Which situation is an example of nonnative species introduction?

Question

A huge volcanic eruption in Washington destroyed many habitats.
A large oil spill in the Gulf of Mexico killed many organisms that lived there.
Horseshoe crabs in the waters of Virginia have been overfished, and their numbers have declined.
Water hyacinths from Asia now grow in the United States and are crowding out animals and other plants.

Answer 1

The situation that is an example of nonnative species introduction is:

Water hyacinths from Asia now grow in the United States and are crowding out animals and other plants.

Nonnative species are those that have been introduced to a new environment where they do not naturally occur, and water hyacinths fit this description as they were brought from Asia and are negatively impacting local ecosystems.