Why did some Central American nations object to Taft's paying off their debt to Europe with U. S. dollars?

B) because they felt it gave the United States too much leverage

Explanation:

William Taft succeeded Theodore Roosevelt as the president of the US, and Roosevelt got very involved in local politics in many Latin American countries, not only Central American countries. His Roosevelt Corollary wasn't very democratic at all, since the US self-imposed the right to act as the police and judge of what happened in Latin American countries. Taft followed Roosevelt's policies, so many Central American countries feared that the US would increase their involvement in local affairs.