Fine, I concede. I maintain that I have never been marked down for using a relative clause to refer to another clause, including on the SAT (800 and 780 writing scores). It’s like saying contractions are ungrammatical.
I found the question online, and the answer key says it’s neither of the answers the OP gave: https://books.google.com/books?id=6peu9mBKw0cC&pg=PA543&lpg=PA543&dq=women+live+longer+and+have+fewer+illnesses+than+men,+proving+that+women+are+the+strongest+sex&source=bl&ots=HKBKVOQkdx&sig=VsvyfzGB1YeuK1ghI1mC2bARKoE&hl=en&sa=X&ved=0ahUKEwiDm5aQkv3KAhWGDSwKHYUMAtsQ6AEIITAC#v=onepage&q=women%20live%20longer%20and%20have%20fewer%20illnesses%20than%20men%2C%20proving%20that%20women%20are%20the%20strongest%20sex&f=false
Crappy link but should bring you to the right point in the book.