A 7-year-old boy is brought to the ED with a 4-day history of fever, sore throat, and difficulty swallowing. They immigrated to the United States from China 6 years ago. Physical exam shows cervical lymphadenopathy and a thick, grayish-white membrane in the posterior oropharynx. Which of the following best describes the most likely causal organism?
A. Gram-negative diplococcus
B. Gram-negative rod, lactose-fermenting
C. Gram-positive coccus, catalase-positive, coagulase-positive
D. Gram-positive rod, non-spore-forming, immotile
E. Gram-positive rod, spore-forming, motile
