What is the most preferred next action for this patient?

A 34 year-old man with one week history of sore throat presents today for fever, hoarseness, difficulty breathing and drooling. On physical examination, his temperature is 102.3f and has inspiratory stridor. What is the most preferred next action for this patient?

A-Admit to the intensive care unit
B-Prescribe broad spectrum antibiotic
C-Throat swab and culture
D-Serology for infectious mononucleosis
E-Ultrasonography of the neck