Respuesta :
Its either B. The Nationalists were reluctant to fight or C. The United States sent U.S troops to aid the Nationalists.
Based on the given options above, the correct answer would be option B. The reason for the communist victory in China is that, the Nationalists were reluctant to fight. Communist victory seemed more and more likely when the civil war gained strength during 1947 to 1949. Hope this is the answer that you are looking for.