The por is been being used in the given sentence to express that A. por means "through" or gives a distance.
When using through in sentence which is a preposition simply means to move from one side to another side, or to let something go to the other side.
Therefore in the given sentence, we can see that "por was used to give a distance through a particular thing.
learn more about through at:https://brainly.com/question/25658352
#SPJ2