Why has the United States sought to encourage the spread of democracy in the world?

Democratic governments, for the most part, support the United States' efforts to expand its economy.

Democratic governments, in general, respect and protect human rights more than other forms of government.

Democratic governments, on the whole, have a greater share of the world's limited natural resources.

Democratic governments, by and large, peacefully coexist with totalitarian and communist governments.

from the given set of options, the most suitable answer would be,

"Democratic governments, in general, respect and protect human rights more than other forms of government."

Explanation:

Since the end of the 2nd world war, after the world polarized clearly into Democratic and Communist sides, USA sought to encourage the spread of communism and thwart the growth of communism.

This was mainly because the, non-democratic, totalitarian regimes of communism was well-known for breaches of human rights.

Moreover, communism enforced command economies and was a major threat to the free trade and free market economic system. This threatened the US Economy and the way of life.