The Parents of an 18-Month-Old Girl Appear at the Emergency

The parents of an 18-month-old girl appear at the emergency department of a hospital with their daughter, who had an abrupt onset of vomiting and incidences of watery diarrhea. The symptoms began 2 days previously at her day care center. She refuses to eat or drink and is very lethargic. What property of the infectious agent causing these symptoms allowed the preparation of a vaccine that could have prevented them?

A) Ability to survive as a temperaturesensitive mutant
B) Identification of an enterotoxin
C) Loss of colonization factors
D) Manipulation of "O" antigens
E) Segmented genetic material