Both Deletions and Insertions Occur During the Evolution of Microbial

Multiple Choice

Both deletions and insertions occur during the evolution of microbial genomes.Insertions bring in new genes that may be useful for the cell,but deletions

A) may increase fitness of a microorganism by eliminating unneeded genes.
B) always result in a severe loss of fitness for the microorganism.
C) are uncommon because they are usually lethal.
D) always result in a severe loss of fitness but keep microbial genomes compact.