Congress had the power to establish laws (but not enforce them), declare war (plus make peace), and had control over the postal service. So there you go.
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.
Answer: Texas was slow to become populated because there were no empresarios there and because the land was expensive before the empresarios.
Explanation: Did it on edge, hope this helps.
The answer would be the first one because during the Nullification Crisis, he sided with the south and agreed with them that they shouldn't have to follow a law they believed to be unconstitutional.
Italy, Greece and France have never been under the Islamic Empire (or any Islamic rulers as far as I know).
Spain was under Islamic leaders for a long time and there was a period of re-conquista later, when the land was re-conquered by the Christians. And in 8th centrury Spain was in fact part of the Islamic Empire.