The Nurse Admits a Client to the Hospital with the Diagnosis

The nurse admits a client to the hospital with the diagnosis of Escherichia coli O157:H7. The client is dehydrated and febrile. During the history phase of the admission, the client states that he doesn't know how he could have gotten sick at the local county fair---the hamburger he bought was well done. Which factor would the nurse predict was most responsible for the transmission of the bacteria?

A) Use of a gas barbecue
B) Improper cleaning of the cooking tools
C) Use of wood instead of charcoal to cook the meat
D) Animals roaming in the fair grounds