When transforming bacterial cells, a researcher is interested in generating bacteria that exogenously express the gene that encodes GFP (green fluorescent protein). After transformation, she finds that no bacteria colonies grew on her selective media. Which of the following best explains the results of her transformation protocol?
a. The concentration of the antibiotics in the selection media was too low, therefore no bacteria grew.
b. Her bacterial cells were not competent so they took up excessive amounts of the GFP-containing plasmid.
d. She forgot the heat-shock step, so the DNA was not forced into bacterial cells.
d. The plasmid that she used contained a sequence that encoded antibacterial resistance.