Howdy, I do not think sentence 13 needs to be revised. This is because I don't think any other answer choices are correct either. So, the answer would be D.
Sentence 13 does not need to be revised. The other sentences do not makesense. They are either fragments or run-ons. They can also use to many words such as which. So, it does notneed to be corrected at all. Hope this helps! :)
