E wins .. "That" and "which" act more or less in the same way in describing only the word that immediately precedes them.
one of the many factors, which are visibly seen.
one of the many factors that are visibly seen.
one of the many factors, which are visibly seen.
one of the many factors that are visibly seen.
![FLO – Therapy at the Club – Pre-Single [iTunes Plus M4A]](http://is1-ssl.mzstatic.com/image/thumb/Music221/v4/a4/11/88/a41188ed-0f2e-e8d5-1163-d59e373cc58c/26UMGIM30046.rgb.jpg/208x208bb.webp)
