Adding a Confidentiality Agreement

We are trying to add a Confidentiality Agreement to our registration process for an upcoming Webinar Meeting. We want attendees to accept the agreement as part of the registration process. 

We had intended to do this via the Registration (edit) -> Custom Questions option but there is a limited character option and our agreement is 153 characters long. 

Does anyone have any ideas how I can add this as part of the registration process for a webinar?