Answer:
Option A. French Emperor Napoleon III tried to gain control of Mexico is the correct answer.
Explanation:
A is correct as Napoleon III ordered the withdrawal from Mexico in 1866, which means that he had nothing to with this war, that started at the end of 19th Century.
All other options led to the outbreak of war, as American newspapers (C) were reporting about the incident surrounding the warship USS Maine.
Question of Cuba( b, d) is the main reason why the war eventually broke out.