Which one of the following statements concerning V. cholerae is true?

A、TheO139serogrouphasthreeserotypes—Ogawa,Inaba,Hikojima;
B、V.choleraeproducesaheat-labileenterotoxin;
C、Allserogroupscausepandemicandepidemiccholera;
D、V.choleraeishumanandanimalpathogen;reservoirinbirdsandmammals;
E、V.choleraeisresistanttoacid,heat,dry