Answer:
The good choices are:
people
civilizations
ideas
Explanation:
People are the protagonists of history, their causes, their fights, their endeavours. But they don´t act alone or isolated; they act witin a social structure, a society, a culture, a civilization. Ideas are engines of change: in the modern world molded by our recent historical experiences, we can point at the extraordinary example of the ideas of Enlightenment, which inspired and guided the formation of Western societies.
