Adding Reasons for Unsubscribing

Hello,

The previous program we used before Marketo had options in the unsubscribe page where people could choose the reason why they unsubscribed or they would select "other" and write their own reason. In Marketo, we're using a Subscription Preference Center where people can either pick to keep receiving one or more of our email subscriptions or unsubscribe from everything. I'm wondering if the only way to add different options for "reason for unsubscribing" is by adding those as boolean fields. It seems a bit messy, but is this the only way?