History question who can help?

I believe the answer is C but maybe someone can back me up on that first before you answer it

the quote by walter cronkite contributes to the central idea of the text by supporting the central idea. cronkite argues that what is deemed “right” for and in america may not be good for other countries. this supports the central idea of the text, that the vietnam war was unpopular in america for multiple reasons- including cronkite’s.