Answer:
Correct answer is b. Nationalist .
Step-by-step explanation:
A is not correct as Communist party in China emerged later, and this party was actually the main opponent of Nationalist.
B is the correct answer as the Nationalist had the main role in overthrowing the old regime, and Kai-shek emerged as one of their leader after WW1.
C is not correct as republican regime was established in China under the leading role of nationalists.
D is not correct as socialism developed in China in a form of communism.