I received a 1099 G/INT from the SC Dep of Revenue. When filing under the 1099 G option, it asks for info on the type of refund from box 8. There is no box 8 on my form.

If there is no information selected or no box 8 indicated on your 1099-G, then just leave it "blank". Box 8 on a Form 1099-G would be checked and included on your Form 1099-G if this was trade or business related income. If it is for a refund of personal income taxes, then no box 8 information is necessary.