Besides the Obvious Fact That Chemical Mutagens Are Dangerous to Handle

Besides the obvious fact that chemical mutagens are dangerous to handle, another major disadvantage to their use is that __________.

A) chemical mutagens activate transposons which cause widespread genetic damage
B) they alter all A- T and C- G base pairing
C) they often result in only dramatic alterations of gene function
D) most of these mutations are immediately lethal
E) most chemically induced changes are detectable only by genetic mapping and sequencing