The correct answer is "C".
The reconstruction was the period that the United States went through right after the end of the Civil War in 1865.
Through a series of negotiations that took many years, Samuel Tilden and Rutherford Hayes both agreed with the Democrats that they will grant concessions in the southern estates in exchange for the political power. Purchase on such lands was not seen as attractive by northern Democrats prior to these arrangements.
In the US part of imperialism is to create a better, more civilized world. It was connected to the idea of "city upon a hill" and Manifest Destiny.
In colonies such as the Philippines, Cuba, Puerto Rico, and Guam, the US introduced school and up-to-date public facilities. A system of democracy was introduced to create self-government.
Of course, there was an economic gain from all of these places and counters the goal of spreading culture. Resources were gained and markets created. In Hawaii, economics drove the annexation and then culture followed.
The late 19th century held a belief in Social Darwinism. This belief held that some people were superior to others and so domination over them was expected if you were the dominate species. Most Americans also believed humans were broken into further species with each race being its own species. This means that "lesser humans" needed to be controlled for their own protection.
The most influential and powerful members of a political party are most likely to be found inside the national party level of the party and at its highest levels. If the President of the United States is from one particular party they are considered the head of the political party nationally making them the most powerful member of the party.