E. coli is a bacterium that is routinely used in cloning experiments and can be grown on artificially synthesized media in the laboratory. One of the strains of this bacterium, XL-1 Blue, is naturally resistant to the antibiotic, tetracycline. A genetic transformation experiment was performed to introduce a plasmid that encodes an ampicillin resistance gene into this strain. Following transformation, an equal number of cells were grown independently on two types of growth media - (A) growth medium with tetracycline alone and (B) growth medium with tetracycline and ampicillin. The number of colonies that grew on medium A was much higher than that obtained on medium B. Which of the following statement(s) explain the above observation?

• Correct answer
  A

  The transformation efficiency of cells is lower than their viability.
• Correct answer
  B

  Untransformed cells also grew on growth medium "A".
• C

  Tetracycline was inhibitory to the growth of bacterial cells.
• D

  Ampicillin did not allow transformed cells to grow on growth medium "B".

Hence, the correct answer is options: 'A', 'B'.