The most accurate statement is:
"Chiang Kai-Shek unified China, and protests erupted in Beijing due to the Treaty of Versailles."
This statement reflects Chiang Kai-Shek's role in attempting to unify China during a time of fragmentation and highlights the widespread Chinese discontent with the Treaty of Versailles, which ceded German concessions in China to Japan. This discontent led to significant protests, particularly the May Fourth Movement in 1919.