The Lancefield grouping system

A)depends on serological detection of polysaccharide and teichoic acid antigens.
B)is used to identify $\beta$ -hemolytic streptococci.
C)is based on a DNA fingerprinting assay specific for streptococci.
D)depends on serological detection of polysaccharide and teichoic acid antigens and is used to identify $\beta$ -hemolytic streptococci.