Obstacles to the Construction of a Trans-Isthmian Canal in the First

Obstacles to the construction of a trans-isthmian canal in the first years of the twentieth century included all of the following EXCEPT

A) The hesitance of the Colombian Senate to ratify the Hay-Herrán Treaty.
B) The malaria and yellow fever that were endemic to Panama.
C) The refusal of Nicaragua's government to negotiate with the United States.
D) British insistence on sharing control of the canal with the United States.