When Sampling Clinical Specimens to Determine the Cause of a Disease

When sampling clinical specimens to determine the cause of a disease, samples are often plated on selective media. The reason for this is to

A) initiate an epidemiological investigation.
B) prevent the growth of normal flora.
C) determine the antibiotic resistance prior to isolation of the pathogen.
D) prevent aerobes from growing.
E) ensure proper biosafety procedures.