Well, the use for the atomic bomb was that it was dropped on Hiroshima and Nagasaki to end the war (With Japan at least) The rest are technically true, but that wasn't really it's use. So A is you best bet here:)
A- Trade
Explanation
(The internet told me so:))
The steam engine was invented by James Watt in 1781
Answer:
He is referring to blacks who lived in Haiti, French colony
Explanation:
The question refers to the statement given by Napoleon Bonaparte while his army was fighting against a band of slaves in Haiti.
