The question that most likely led the scientists to choose bacterial cells for the process of extracting insulin is:
d) Which organisms reproduce very quickly?
Bacteria reproduce rapidly, which makes them an ideal choice for producing large quantities of insulin through biotechnology. This allows for efficient production and purification of the protein needed for individuals who cannot produce it naturally. While other factors may also be relevant, the rapid reproduction rate is a key determinant in the choice of bacteria for biotechnological applications.