Well, it can't be the Cuban missile crisis, that was before he was president, he was the vicepresident.
the bombing of Japan happened about 20 years earlier.
He did sign the Civil Rights act into Federal Law, and that was very significant.
The correct answer to this open question is the following.
Although the question does not include options, we can comment on the following.
A key similarity in the policies of the rulers of African states such as Ethiopia in the period circa 1200–1450 was that some African states were capable to overcome geographical barriers and other internal issues to establish trade and diplomatic relationships with other states in Africa, Asia, and Europe.
In the case of Ethiopia, the ruler of Italy received important Ethiopian diplomats that visited Naples in 1450. The Emperor of Ethiopia was King David, and he sent to Naples a man called Pietro, who notify the King of Italy that Ethiopians professed the Christian religion.
Probably the most important change that happened at the time was that C - Women worked jobs that had ben held almost exclusively by men.
Due to the fact that the majority of men, or at least a good portion of them, were on the battlefield in Europe, women had to take over the role in certain key areas that were necessary for the victory of the US.