The best answer would be the first one: Bill and Allen both spent all day Saturday raking leaves to the curb for pickup. The second one isn't even a full sentence; the third has improper punctuation, and the fourth one isn't even a proper sentence and it has improper punctuation as well. So, this goes down to the first answer. It is a complete sentence, it fully describes them both doing the same thing like the original sentence does, and everything is described just like the original.
