Working from an earlier discovery of Charpentier’s, chemists Emmanuelle Charpentier and Jennifer Doudna—winners of the 2020 Nobel Prize in Chemistry—re-created and then reprogrammed the so-called “genetic scissors” of a species of DNA-cleaving bacteria blank a tool that is revolutionizing the field of gene technology.
Which choice completes the text so that it conforms to the conventions of Standard English?