Question

what was most surprising about the outbreak of the chinese civil war?
○ chiang kai - shek switched sides to launch an attack on the communist party.
○ the communist party leaders once had declared their opposition to war.
○ the nationalist party and the communist party formerly were aligned.
○ the nationalist party had much to lose and little to gain in a civil war.

Explanation:

Before the civil war outbreak, the Nationalist Party (Kuomintang) and Communist Party had formed the First United Front to fight warlords and foreign imperialist forces. Their sudden turn to open conflict was the most surprising element, as they had been aligned allies shortly before. Other options are less accurate: Chiang Kai-shek did not "switch sides" (he led the Nationalists, the established ruling force), the Communists had not declared formal opposition to war in a way that made the outbreak surprising, and the Nationalists had significant incentives to eliminate the Communists to consolidate power.

Answer:

The Nationalist Party and the Communist Party formerly were aligned.