The 1960s counterculture had the most lasting impact on what? // A) the American political process // B) attitudes toward lifestyles and...

This is not a question that can really have an obectively
correct answer.  I would suggest that you look for what your textbook says is the
correct answer.  The impacts of the counterculture can certainly be debated and at least
two of these answers could be seen as correct.

I would
argue that the best answer is B.  I would argue that the counterculture had a greater
impact on American society than on the political process.  I would argue that the
counterculture helped make Americans rethink things like the role of women and
minorities in society.  It helped bring about the "sexual revolution" that has impacted
US culture.  These changes, I would argue, are greater than its impact on the political
system.