On a somewhat related note, I'd change the wording from "unsubscribe options" to "subscription options" to avoid accidentally communicating to leads that they are unsubscribing when they are actually only reducing their email frequency.
Some color would be helpful on what exactly that field is mapped to, and what campaigns you have triggering off of that field. Are you adding people to static lists to manage your subscription preferences, or using fields on the lead records that you look for when you run email campaigns?
Justin is correct.
You need to design the form as well as the backend of this. I would also design the form and page to be more friendly and encourage "subscriptions" rather than Unsubscribe options.
Each sub option has a corresponding field checkbox (which should exist in Marketo and SFDC)
or whatever you want. Next to each option I would have a link to a pop up example of the content and the expected frequency (1/month, 2x/week.) so people know what they are getting into.
When the lead says Unsub=T, a campaign flips the others to F
You then have a series of lists that look for Event Invitation, etc = T so you know whom to send to.
Frequency is hard to implement because it requires a lot of logic and smart list use and your team will have to use this exclusion list. What you can do that is easier is say "Pause Me" like Marketo does: