The accurate statement that summarizes Chiang Kai-Shek's role in modernizing China and the Chinese reaction 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 and modernize China, as well as the widespread protests against the Treaty of Versailles, particularly the decision to grant Japanese territories previously held by Germany to Japan, which sparked outrage among the Chinese populace.