The period between 1870 and 1914 saw a Europe that was considerably more stable than that of previous decades. To a large extent this was the product of the formation of new states in Germany and Italy, and political reformations in older, established states, such as Britain and Austria. This internal stability, along with the technological advances of the industrial revolution, meant that European states were increasingly able and willing to pursue political power abroad.
Renaissance
The age of enlightenment began in the 1650's, so it would need to be a continuation of an era that ended around the 1650's. Since the Renaissance lasted from 1350 - 1650, that makes it the most likely answer.
The correct answer is C.
In fact the other options provided state the weaknesses that the Europeans encountered in their conflicts against the native Americans. They did not know the land, whose wilderness added extra dificulties for strangers, and in the case they needed reinforcements, the process of bringing them from Europe was long and costly.
But these weaknesses were rapidly outbalanced due to the huge superiority that the Europeans had in terms of weaponry if compared to the natives. They already knew gunpowder, while, natives Americans were still using bows and arrows. Moreover, the Europeans had properly organized armies, with its hierarchies, different units, experienced and skilled commanders, etc.
Depending on the time, it could be the Phoenicians ( I think this is the best answer; this is what they're known for best) or later in time, the Romans (but they had colonies also elsewhere).
It gave women work because of all the lives lost