Question

What message did the Roosevelt corollary send to the rest of the world?

Answer 1

The main message that the Roosevelt corollary sent to the rest of the world was that the United States would not sit idly by while European nations "tangled" in the business of other European nations with regards to their holdings in Latin America. It was an assertion of American strength. 

Answer 2

If this is what i think it is then your answer is: B.) The US was in charge of the Western Hemisphere.