A Patient Shows the Presence of Antibodies Against Diphtheria Toxin

A patient shows the presence of antibodies against diphtheria toxin. Which of the following statements is FALSE?

A) The patient may have the disease.
B) The patient was near someone who had the disease.
C) A recent transfusion may have passively introduced the antibodies.
D) The patient may have been vaccinated.
E) The patient may have had the disease and has recovered.