The correct answer to this open question is the following.
Dante's "The Divine Comedy" BEST illustrates the ideals of humanism because it was written in a vernacular language that is not difficult to understand.
This was a characteristic of Renaissance times. Renaissance writers focused on the dignity of humans and the value of the individual and reflected it on its humanist works. This was the case of Dante and Petrarch. The movement called "Humanism" started in Italy in the late 14th century, beginning of the 15th.