Final answer:
The approximate diameter of plasmids from an E. coli cell is between 0.02 µm and 0.05 µm.
Step-by-step explanation:
The approximate diameter of plasmids from an E. coli cell is 0.02 µm to 0.05 µm. Plasmids are small circular supercoiled non-chromosomal DNA that exists in addition to the bacterial chromosome. Since the entire E. coli chromosome, which is significantly longer, is coiled and packed within the nucleoid of the cell, it is reasonable to expect that plasmids are quite small in comparison. Considering that prokaryotic cells, such as those of E. coli, range from 0.1 to 5.0 µm in diameter, the only viable options for the diameter of plasmids would be 0.02 µm or 0.05 µm, making option a or b correct.