If you have the resources to set an event, I do not understand why you are barred from using a variable or link tracking. As Jennifer said, you options are not great in that case.
However, IF YOU WERE able to use a variable, I would use a single variable for user-entered form data. In your example the format might be:
<formID>_reas:<option>|clin:<option>
For example: mkappt_reas:3|clin:1
The string is a concatenation of the selected options. It assumes there is a trigger for the submission of the entire form such as a submit button. Tracking the selected options as users go through the form will not work well.
The first element identifies the specific form. Following the underscore delimiter are the name value pairs for the fields and selected options in the form. Each field name-option pair is separated by a pipe delimiter.
You can use numeric ids or alpha ids or a combination (as in my example) as long as you keep with in the character counts for the evar (250) or prop (100).
Assuming different forms have different options, I would create a classification for the FromID and leave it at that. Classifying the options may be too complicated if you have a lot of different fields across multiple forms.