Figure 19.1 -In the experiment shown in the figure above, Tonegawa and his colleagues were able to express fi- globin in an antibody- producing cell that normally does not express fi- globin. They achieved this result by splicing an enhancer from an antibody- producing gene into the protein- coding portion of the fi- globin gene. They then introduced this recombinant gene into cultured antibody- producing cells. Why was the choice of Antibody- producing cells-rather than, say, muscle or skin cells-critical for the success of this experiment?
A) Only the antibody- producing cells have the correct regulatory transcription factors to bind to the enhancer. B) Only the antibody- producing cells are capable of expressing recombinant genes. C) Only the antibody- producing cells have the correct set of enhancers, promoter- proximal elements, and promoters. D) Only the antibody- producing cells have the correct set of enhancers. E) Only the antibody- producing cells have the correct set of promoter- proximal elements.