What is the author’s purpose in writing "a modest proposal"? to submit a plan to solve an important societal issueto draw attention to an issue that is plaguing his countryto show that only an extreme solution can fix povertyto defend those who have avoided falling into poverty

to draw attention to an issue that is plaguing his country

By using such inflammatory language and such an extreme proposal of eating the children of the poor, Swift is using satire to bring light to an issue that is really important in the country. There is too much poverty and the government and rich people aren't doing enough to help, so he went to drastic measures to draw attention to that. 

The correct answer is: c claim of cause and effect