Read the excerpt from "Keynote Address.”

The success of our economic system has freed [young people of today] in ever-increasing numbers from the tragedies of premature mortality and early labor. It has built the schools in which they are being educated to higher levels than ever in our nation’s history. And this progress has been achieved in a political system that not only admits but safeguards the right of dissent.

So it should hardly surprise us when the children of such progress demand to be heard when they become aware of inequities still to be corrected. Neither should we fear their voices. On the contrary, whether we know it or not, the marching feet of youth have led us into a new era of politics, and we can never turn back.

How does the speaker best develop logos in this excerpt?

by explaining why he is hopeful that young people will eventually be able to pursue an education
by trying to engage the audience with language such as “the marching feet of youth”
by including the opinions of young people on current progress
by listing achievements made in recent history