Laboratory Experiments About Bacterial Mutation Rates Have Demonstrated Which of the Following

Multiple Choice

Laboratory experiments about bacterial mutation rates have demonstrated which of the following?

A) Bacterial mutation rates rarely evolve in short-term laboratory experiments; they are a relatively fixed feature of a species biology.
B) In short-term laboratory experiments, bacterial mutation rates often evolve to be higher because higher mutation rates result in higher fitness.
C) In short-term laboratory experiments, bacterial mutation rates often evolve to be lower because mutations are typically deleterious for organisms.
D) Depending on the experiment, bacterial mutation rates sometimes evolve to higher rates, and other times evolve to lower rates.