Hi Eric,
Thank you for your help,
I took the repeat region and was trying to figure out how.
And I realized I was thinking harder than it has to be.
I set the option as "hidden" on Add to cart server behavior's binding panel (set the recordset to option column as well), then changed the form type from "hidden" to "radio". Then I repeated the option, it now seems working just fine.
Sorry for the trouble!
Rika