A 4-Year-Old Girl Is Brought to the Emergency Department by Her

A 4-year-old girl is brought to the emergency department by her parents because of fever, coughing, difficulty swallowing, and increasing shortness of breath for 6 hours. Physical examination shows cervical lymphadenopathy and a blue-gray film over the posterior pharynx. Microscopic examination of a throat culture shows bacilli arranged at acute angles. Specialized staining of the sample shows metachromatic granules at the polar region. Which of the following best explains the pathogenicity of the organism most likely responsible for this patient's condition?

A) Activation of electrolyte transport
B) Blockade of neurotransmitter release
C) Cellular membrane disruption
D) Impairment of protein synthesis
E) Widespread T cell activation