You Want to Know Whether the Virulence Genes Present in Bordetella

You want to know whether the virulence genes present in Bordetella pertussis are evolutionarily related to genes in the less pathogenic species B. bronchiseptica or if the virulence genes were acquired via horizontal gene transfer. What characteristic(s) would you compare to answer this question?

A) percentage of GC content and codon usage
B) genome size and number of introns
C) number of genes in the pan genome
D) ribosomal binding site and intron sequence