What is the main idea of this article?

the correct answer is option d. the nature of democracy. on november 19, 1863, president abraham lincoln delivered his famous gettysburg address in gettysburg, pennsylvania. in his speech, rather than focusing on details of the war (soldiers, casualties, aftermath of battle), lincoln invoked the very nature of democracy, that power ultimately comes from the people, when stating, “government of the people, by the people, for the people shall not perish”. these words mean that democracy is a government by the people (citizens) in which the supreme power is vested in the people and exercised directly by the people or by their elected representatives for the benefit of all citizens. the survival of democracy in the united states is one of the reasons why this speech so significant today.

the sentence that avoid faulty coordination is:

culture, which is well represented in philadelphia, plays a major role including theatre, music, and the visual arts.  

faulty coordination occurs when the writer gives equal importance two different ideas (clauses) which in fact are not equivalent. in order to correct a misplaced clause or idea, the writer can place less important or emphatic ideas in a relative clause as in the previous sentence.