Immediately following a posterior superior alveolar block injection, the patient's face becomes quickly and visibly swollen. The immediate treatment should be to

use pressure followed by cold packs over the swelling.

use hot packs over the swelling.

refer the patient to a hospital.

administer 100mg hydrocortisone intravenously.

administer diphenhydramine hydrochloride (Benadryl) 50mg intravenously.