C. Classical humanism and realistic paintings became popular.
The Renaissance was a time of great learning and growth, it especially popularized humanism which directly translated into the art of that time period. So A, B, and D are unlikely to bee the correct choices. Therefore, C is the correct answer.
Knights had to perform military services for the king in exchange for a portion of land
The correct answer to this open question is the following.
Although there are no options attached, we can answer the following.
I think this quote refers to the Panama Revolution of November 1903. Let's remember that United States President Theodore Roosevelt supported Panama to get its independence from Colombia.
The federal government had many economic and political interests in the region, specifically, it wanted the control of the Panama Canal that the French had started to construct at the end of the 1800s.
Roosevelt created the corollary of the Monroe doctrine in which the United States sent a clear message to European superpowers saying that it was only the United States the ones that were going to intervene in the foreign issues of Latin America. No more European nations.
A) to amend the Articles of Confederation
Between 1783 and 1787 some events occurred in the US that proved the Articles of Confederation were not working. For many leaders Shay's Rebellion was the final straw.
State representatives came to Philadelphia to amend the Articles of Confederation. However, it was quickly realized that a whole new system needed to be created to fix the issues the Articles presented. Representatives offered different options but overall a strong central government was needed to fix the concerns. Out of the convention, the Constitution of the United States was created and has remained the law of the land since 1788.