Originally, the Constitution said that senators were chosen by _(state)_ legislatures. The _(17)_ Amendment changed this. Now, Senators are chosen by_(a direct vote)_.
Nation is its citizens and Jefferson stresses basically that that is why the people must participate in the government. The government is of the people for the people which means that the government is made up from the citizens of the United States. It is those same citizens that, by their right to vote, choose who will do their will in the government. Precisely because the people choose who will be in the government is the reason why they must be more active as it will decide what policies were going to be pushed.
C and D are wrong due to the fact that it does not occur in July and there is no direct sunlight. Also thing it’s B or A but I’m thinking its A due to the fact it doesn’t always occur on the 21st but also the 20th.
Mexico's economy is the 15th largest in the world in nominal terms. Hope this helps :)