Social darwinism is the theory that the american frontier stopped people from rebelling in the united states life consists of competitive struggles in which only the strong survive only countries with colonies can compete in the world market the united states should expand its territory from the atlantic and the pacific oceans

The answer would be : Life consists of competitive struggles in which only the strong survive

It really similar with Darwin's "Survival of the fittest" theory
Social Darwinism is some sort of ideology, which apply the biological concepts of natural selection to the real modern world. According to this theory, the people with no power in society are similar with the creatures at the bottom of the food chain

My best answer choice would be b.  hope this ! : )