How does the idiom "think globally, act locally" continue to be useful for present-day environmentalism?                 a.  it's used to explain that the environment is an inherently global and large-scale concept.      b.  it's used to create grassroots support for oil spills, dirty water, and polluted air.      c.  the lack of government solutions for global warming has made groups focus on local issues.      d.  environmentalist groups use the idiom to mirror the efforts of antiwar movements