Why Was It Necessary for the Lab to Inoculate a Sample

Why was it necessary for the lab to inoculate a sample of the incubated tetrathionate broth onto a medium selective for Salmonella?

A) To confirm that the bacteria in the broth is Salmonella and not another bacterial species.
B) To confirm that the bacteria in the broth is E. coli and not another bacterial species.
C) To check whether the Salmonella has the ability to form endospores.
D) To confirm that Salmonella is a bacterium and not a virus or protozoan.
E) To confirm that Salmonella is a facultative anaerobe and not an obligate acidophile.