Genomes Are Considered to Be Mosaic

Genomes are considered to be mosaic. Which of the following statements provides the LEAST support for this idea?

A) E. coli can receive plasmids from other strains of Gram-negative bacteria.
B) The archaeon Methanocaldococcus jannaschii has many proteins with sequence homology to proteins found in both bacteria and eukarya.
C) Agrobacterium can transfer plasmids to plants.
D) Genome sequencing and informatics has revealed a variety of homologous genes throughout the domains of life.
E) Genes from Mesorhizobium loti have been found in other new species of Mesorhizobium.