The Sentence ends having a string of "wh-" noun clauses. These clauses aren't concerns, so the final a person should also not be a matter. "Which 1 could be the best" is obviously a matter structure, so it is sensible that " mike rodentmike rodent 16k1414 gold badges120120 silver badges199199 https://share.evernote.com/note/74e6f5bf-4e0f-8a5f-1a27-70e011ebb01c