Researcher inserts a DNA segment at the BamHI recognition site within a plasmid; this site is located within the tetracycline resistance gene. This plasmid also has a gene for ampicillin resistance. Following DNA transformation, the researcher must differentiate the bacteria that have taken up the recombinant DNA from those that have taken up either the foreign DNA only or intact plasmids. In doing so, the researcher should select the bacteria that
A. will grow on ampicillin but are sensitive to tetracycline.
B. are sensitive to both antibiotics.
C. are resistant to both antibiotics.
D. will grow on tetracycline but are sensitive to ampicillin.
E. grow only on an enriched medium.