It is really confusing now. I contacted to USCIS on the number given above. I requested him to tell me whether it is A12 or C19 to put under "Eligibility Category". Actually, he did not want to tell me (or the guy did not know about this, not sure). He said, due to privacy policy they are not in a position to tell me on the phone. He suggested me to contact either the local immigration officer by taking an appointment or consult an immigration attorney.
If any body knows for sure, can you please share your experience.

IS IT (a)(12) OR (c)(19) ????????