Question

rachel carson helped usher in the modern environmental movement in the 1960s with her book silent spring, which alerted the public to threats from __

○ overhunting of birds
○ deforestation
○ urban development
○ pollution and toxic chemicals

Explanation:

Rachel Carson's "Silent Spring" focused on the dangers of pesticides (toxic chemicals) and related pollution, highlighting their harm to the environment, wildlife, and human health, which spurred the modern environmental movement. The other options (overhunting of birds, deforestation, urban development) were not the primary focus of "Silent Spring" as its core was about chemical pollution from pesticides.

Answer:

D. pollution and toxic chemicals