In "a modest proposal," why does swift intentionally use false premises as a basis for his arguments?
to signal that he is actually writing a satire
to suggest that his proposal is truly genuine
to lighten a serious topic with playful humor
to prove that he has made some valid points

Choice 1, to signal that he is actually writing a satire. "a modest proposal" is a satirical work that suggests something completely off the wall to help the economy in swift's country, just to make a point that everyone's misguided suggestions are getting them nowhere. giving false premises wouldn't increase the honesty of his proposal, so choice 2 is incorrect. if one wants to show their true belief in a proposal, they'd offer real evidence. choice 3 is incorrect as well. while satire sometimes does cause people to laugh, that isn't swift's purpose--he wants to drive people to think, and he wants to point out the obvious issues with the system they have currently. choice 4 is incorrect because his points are not valid. his "false premises" basically invalidate all of his points because he has no true basis for any of his arguments.