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