A representative character is one who stands for D, 'humanity in general'. Because it doesn't stand for only a certain type of personality, an ethnic or a political group, but rather for the whole humankind.
Because science was not as advanced as today, readers during the earlier era were easily convinced. Therefore, the answer would be A.
The correct answer is b. whether or not to cast himself as the main character.
He didn't want to make it too obvious that the Divine Comedy insulted many of the locals and many rich and wealthy people of power, and casting himself would certainly point towards that.
Shorter sentences work to speed up the pacing of the story.
