"opposition to the Vietnam War and support for civil rights struggles" is the proper answer. The other choices:
a) a return to the music, clothing styles, and other fads of the 1920s. - wrong because counterculture was a revolt against the "traditions"
b) moral conservatism and a resistance to involvement in politics. - wrong
d.) sit ins, marches, and sit-down strikes demanding workers' rights. - doesn't seem plausible
