Question

Which of the following would prevent Japanese intervention in its neighboring island of the Philippines?
the Gentlemen’s Agreement
the Roosevelt Corollary
the Root-Takahira Agreement
the Treaty of Portsmouth
the Teller Amendment

Answer 1

I believe the answer is the Root-Takahira Agreement
the Root-Takahira Agreement was enacted in November 30, 1908 in which the Japanese Government first acknowledge the territory of Hawaii and Philipines as  a part of United States' territory. In exchange, Japan require United States to let off our influence in southern Manchuria.

Answer 2

for plato it's the Root-Takahira Agreement