What did President Taft's administration do that upset Teddy Roosevelt so much
that he decided to run for President in
1912?
A. Taft was caught in an oil business scandal.
B. Taft used the "big stick" diplomacy.
C. Taft stopped all of Roosevelt's trust busting efforts.
D. Taft's secretary of the interior sold some of the National
Parks land Roosevelt had reserved.

C. Taft stopped all of Roosevelt's trust busting efforts.

Explanation:

President Taft's administration was supposed to be an extension of Theodore Roosevelt's administration as he promised to continue the good works of the former president.

However, he came into office and sacked the cabinet ministers of Theodore Roosevelt and worked hard to undo Roosevelt's trust busting efforts.

This made Roosevelt so angry that he decided to run against his former ally.