Which of these excerpts follows the format of a persuasive essay?
i’ve been to the mountaintop
by martin luther king jr (excerpt)

it means that we've got to stay together. we've got to stay together and maintain unity. you know, whenever pharaoh wanted to prolong the period of slavery in egypt, he had a favorite, favorite formula for doing it. what was that? he kept the slaves fighting among themselves. but whenever the slaves get together, something happens in pharaoh's court, and he cannot hold the slaves in slavery. when the slaves get together, that's the beginning of getting out of slavery. now let us maintain unity.

farewell address to congress
by general douglas macarthur (excerpt)

let civilian voices argue the merits or demerits of our processes of government; whether our strength is being sapped by deficit financing, indulged in too long, by federal paternalism grown too mighty, by power groups grown too arrogant, by politics grown too corrupt, by crime grown too rampant, by morals grown too low, by taxes grown too high, by extremists grown too violent; whether our personal liberties are as thorough and complete as they should be. these great national problems are not for your professional participation or military solution. your guidepost stands out like a ten-fold beacon in the night: duty, honor, country.

taming the bicycle
by mark twain (excerpt)

the self-taught man seldom knows anything accurately, and he does not know a tenth as much as he could have known if he had worked under teachers; and, besides, he brags, and is the means of fooling other thoughtless people into going and doing as he himself has done. there are those who imagine that the unlucky accidents of life—life's "experiences"—are in some way useful to us.