A. a country should use its military to establish an empire (apex)
This answer depends greatly on the time period in question, but generally speaking it is true that the presence of many rivers and mountains protected China from invaders, and allowed their culture to grow with little outside influence, with the exception of Mongolian invasions from the north.
Communism took over in many areas, and the Secretary of State of the U.S. offered a plan. Sorry if I'm wrong.
