Hi Keira,
The "(optional)" label you're seeing is a styling convention set BC Government's particular implementation or Orbeon. We suppress the "*" markings for required fields and add "(optional)" to any fields not required.
Unfortunately, there's a discrepancy between what is presented to the user when deployed, and what you see when you test the form in Form Builder; they use two different rendering engines and their styles aren't properly aligned. This is mentioned in our CMS Forms manual and you would see the correct display in CMS Lite.
Questions about the BC Government's implementation of Orbeon ("CMS Forms") should be directed to me through normal email. I'm your primary support.
Charles Ormiston