The sentence ends with a string of "wh-" noun clauses. These clauses are certainly not concerns, so the last a single should also not be an issue. "Which 1 is definitely the best" is clearly an issue format, so it is smart that " All natural childbirth natural gasoline natural https://share.evernote.com/note/8017dd9b-bae1-b7b2-e7a5-981f51e2ee16