A nonstop flight to Europe
<em>B. North America.</em>
Explanation:
Christopher Columbus actually never explored North America. The first person to explore North America goes to John Cabot, although there are numerous studies on how vikings were actually the first ones to explore North America. John Cabot, also known as Giovanni Caboto, went exploring when he got sent by Henry VII, and found North America in 1497.
Secret diplomacy was a major factor based on the fact that led to fear between all the nations and confusion. Nationalism and imperialism is a factor, scramble for Africa, Archduke fradana has some ties based that his death lead to more retaliation in the Balkans which wanted to be independents do Austria-Hungary and Russia fought over for.