Remove the decline option from calendar invitations

I have a client that would like to have the decline option removed ( made a grayed out option ) on meeting invitations that they send. Is this tied into the mail template file?

Subject: You WILL attend this meeting whether you want to or not!

Subject: Huh?

I think that this would drive the invitees crazy. They would then be only able to accept an invitation or ignore it. It sounds like the people setting up meetings don’t care to know who will attend and who won’t. They should select the Delivery Options checkbox, “I do not want to receive replies from recipients”.