A patient who is receiving N2O/O2 complains of dizzness, headache, and lethargy. What is the best treatment that the dentist can order for the patient to alleviate the symptoms?

Place a topical patch on the injection site

Administer 100% O2 for 3 to 5 minutes

Spray a topical anesthetic at the back of the throat

Inject lidocane 2% through incisive nerve block