(A) The United States was preoccupied with World War I.
(B) ** Workers had to combat deadly tropical diseases.
(C) Workers were provided with obsolete construction tools.
(D) The United States was unable to gain control in the region.
EXPLANATIONS BELOW
Concept note-1: -“There is too much water, the rocks are exceedingly hard, the soil is very hilly and the climate is deadly. The country is literally poisoned, ” complained senior French engineer Adolphe Godin de Lépinay. Outbreaks of dysentery and epidemics of yellow fever and malaria decimated the workforce.
Concept note-2: -The Panama Canal was the construction miracle of the beginning of the 20th century. It also was a great demonstration of malaria control based on an integrated mosquito control program enforced by the military.
Concept note-3: -Over 22, 000 workers died during the French effort to build the Canal, many of them from malaria and yellow fever. The symptoms of yellow fever were terrifying: fever, headaches, back pain, extreme thirst, and black vomit from internal bleeding.
Concept note-4: -An estimated 12, 000 workers had died during the construction of the Panama Railway and over 22, 000 during the French effort to build a canal. Many of these deaths were due to disease, particularly yellow fever and malaria.