Which of the following is NOT a reason that metagenomics is particularly useful for studying microbes?

A) Many bacteria that cannot be cultured in the laboratory can now be studied.
B) The composition of natural microbial communities can be reconstructed.
C) The microbiome of individuals can be compared to understand the basis of disease.
D) Previously unknown species of bacteria and new gene families have been discovered.
E) The genomes of somatic cells in a human individual can vary significantly.