choices 1, 2, and 5 represent the same main idea. choices 3 and 4 are details--the fine print, so to speak, of swift's proposal. the fact that they can sell their children to be eaten after a year isn't a main idea; it's just another small factor in his overall suggestion. the same can be said for his point about men caring better for their wives. again, this is a detail and an "extra benefit," but it doesn't capture the overall ideas in his proposal like choices 1, 2, and 5 do.