Which of the following is an acceptable means to obtain the gingival retraction that isneeded when using an elastomeric impression material for making a final impression in fixed prosthodontics?
1. Electrosurgery.
2. A moist retraction cord.
3. A copper band that is removed when the impression is made.
4. Using a heavy body material in the impression tray.

(1) (2) (3)

(1) and (3)

(2) and (4)

(4) only

All of the above.