A fistula found in association with a non-vital tooth should be
1. cauterized to remove the epithelium.
2. traced to source with a gutta-percha point on a radiograph.
3. treated with combined surgical and nonsurgical root canal therapy.
4. treated with nonsurgical root canal therapy.

(2) and (4)

(1) (2) (3)

(1) and (3)

(4) only

All of the above.