Identification of the Antigenic Type(s)of Streptococcus Pneumoniae in Two Patients

Identification of the antigenic type(s) of Streptococcus pneumoniae in two patients with pneumonia is useful in

A) determining the appropriate antibiotic treatment.
B) determining whether the patients are producing antibodies.
C) identifying the source of the bacterium.
D) identifying whether the bacterium will grow easily in a laboratory.