24 YO female. 3 days history of slurred speech, double

24 YO female. 3 days history of slurred speech, double vision, dyspnea. require mechanical ventilation to maintain her respiration. one week ago she went family picnic. Other family had vomiting or diarrhea after this picnic. O/E large unreactive pupil, facial weakness, no movement of palate and tongue. Sensation intact. Next?? a. Antitoxin
b. IFN
c. pyridostigmine
d. riluzole