which of the following sentences from Lisa Wilson Strick essay, Nonsexist Child-Rearing: The New Parent Trap? is the best example of a thesis statement?

"Boys were expected to be rough-and-ready troublemakers, while girls were supposed to be pristine and demure."

"We found ourselves looking at our healthy, able children and feeling like failures."

"To develop such impossible well-rounded individuals some parents are going to extremes."

"Our visions of the perfect non-sexist human being sometimes blinds us to simple facts of nature."