Disparate animal groups, such as ruminants and humans, can digest a variety of plant fibers because they harbor cellulase-producing bacteria such as

A) Staphylococcus aureus and Bacillus subtilis.
B) Salmonella and Shigella.
C) Escherichia coli and Enterococcus faecalis.
D) Bacteroides and Ruminococcus.
E) Escherichia chrysanthemi and Erwinia uredovora.