I don't think a correction is necessary. Both parts of the sentence are already in the present tense. Plus, the use of "us" in the beginning of the sentence indicates a personal attachment.
pls include the passage of what it is that you have read so i can answr your question
It expresses that the people are working together to make a more perfect union and make the United States of America a legitimate country with a constitution. The people in power are chosen by the general population, so it's a form of representative democracy.
The answer would be b. That seems to make the most sense.
