I need help

What was the main point of truman doctrine ?

Me i really need which of these was an accomplishment of the han dynasty? the invention of the seismograph finding a water passage to europe the invention of the ballpoint pen the invention of the abacus

Part a: which statement identifies the central idea of the text? a: the north was more powerful than the south and was always going to be the victor of the civil war. b: despite the obvious strength of the north, the outcome of the war was unpredictable at the time. c: the united states underestimated the strength of the south, giving it the upper hand. answer !