The statement that accurately summarizes the role Chiang Kai-Shek had in modernizing China and how the Chinese reacted to the Treaty of Versailles is:
Chiang Kai-Shek unified China, and protests erupted in Beijing due to the Treaty of Versailles.
This response correctly reflects Chiang's efforts to unify China and the widespread discontent among the Chinese population regarding the Treaty of Versailles, especially the decision to transfer German concessions in Shandong to Japan, which sparked significant protests, including the May Fourth Movement.