Which Statement About Microbiomes And/or Biofilms Is True

Multiple Choice

Which statement about microbiomes and/or biofilms is true?

A) Microbiome communities always occur as biofilms.
B) Biofilms are always detrimental to an organism's health.
C) The species present in an intestinal biofilm are considered part of the microbiome.
D) Microbiomes are easily studied, as most of the species present have been fully characterized.
E) Microbiomes are composed exclusively of bacterial communities.