How did communist and nationalist forces influence china? select all that apply. a. they encouraged the opening of china to foreign trade. b. they caused political conflict and civil war. c. they worked together to overthrow china's last imperial dynasty. d. they prevented the japanese from occupying china. e. they encouraged chinese officials to launch democratic reforms. f. they split china into a northern communist nation and a southern non-communist nation. g. they gave rise to authoritarian forms of government. !