In , bacteriologist Alexander Fleming returned to his laboratory after a summer vacation and noticed something unusual in a discarded petri dish. A mold called *Penicillium notatum* had contaminated the dish, preventing the growth of surrounding staphylococci bacteria. Recognizing the significance of this occurrence, Fleming realized that the mold was producing a substance that could kill harmful pathogens. Although he published his findings, he did not have the resources to purify the active agent. Consequently, a couple of smart guys at Oxford University later finished the job, enabling the mass production of penicillin during World War II.
Which of the following choices best maintains the formal and objective tone established in the passage?
- ANO CHANGE
- Bsubsequent investigations by a pair of highly esteemed academicians at Oxford University brought the process to its ultimate fruition
- researchers at Oxford University later purified the compoundCevap
- Dtwo researchers at Oxford University subsequently followed up on this work later on and succeeded in purifying the drug