During dental treatment, a 62 year old insulin-dependent diabetic, suddenly complains of severe, crushing, retrosternal pain. The appropriate initial management would be to stop treatment and
1. administer sublingual nitroglycerin.
2. administer 100% oxygen.
3. monitor the patient.
4. administer 50% dextrose intravenously.

(2) and (4)

(1) (2) (3)

(1) and (3)

All of the above.

(4) only