Who took the photograph above? why was it taken? what was it's purpose?

Ansel Adams is the photographer who tool this picture, He was hired by the Sierra Club to create a book of photographs of American parks. The book was distributed to Congress, and successfully convinced its members to pass legislation that would preserve American parks by creating a number of national parks and preserves.

i would think b and c

name the above painting and its artist. how has the artist used balance, variety, and movement in this piece to emphasize the man waving the cloth, in the upper right-hand corner? be specific in your response.