Answer: C. The Sierra Club was established and is still running today to protect the Sierra region.
Explanation:
John Muir was a famous environmentalist in the late 1800s and the early 1900s who fought for the protection of the U.S. mountains, rivers, and generally the U.S. wilderness.
He founded the Sierra Club which has continued his legacy and continues to take care of various wilderness areas in the United States including in Sierra where it lobbies government whenever a perceived threat is noticed.
