The Rate of Nosocomial Infections Is Often Relatively High in Emergency

The rate of nosocomial infections is often relatively high in emergency room settings. Explain the most likely reason why this might be so.

A) Often, the most acutely ill or most traumatically-injured individuals are found in emergency rooms. The combination of these two groups can lead to very easy spread of infectious agents into exposed tissues/organs of individuals in such physical locations.
B) Emergency rooms are inherently less sterile than other areas of hospitals due to the speed of the treatments. Speed becomes the desired trait over cleanliness during the response.
C) Emergency rooms are inherently less sterile than other areas of hospitals due to the large number of homeless people/drug addicts/prostitutes that seek treatment in these locations.
D) Patients brought into emergency rooms are often brought in by ambulances/EMTs. These individuals are less cautious with universal protocols for protection of both themselves and patients than physicians are.