The Fluctuation Test of Luria and Delbruck Showed That

The fluctuation test of Luria and Delbruck showed that:

A) a selecting agent can affect mutation rate in E.coli.
B) mutations can arise spontaneously before exposure to the selecting agent.
C) mutations in E.coli occur at a relatively high frequency.
D) the mutation rate in E.coli fluctuates greatly from one generation to the next.
E) the T1 phage can act as a mutagen as well as a selecting agent in E.coli.