What new piece of evidence, supporting biogenesis, was provided by Pasteur's experiment? A) S-necked flasks prevented both microorganisms from contaminating the broth and air from entering the flasks. B) S-necked flasks prevented microorganisms from contaminating the broth, even though air still entered the flasks. C) Pasteurs experiments with S-necked flasks supported the hypothesis that microorganisms are not found in the air. D) Pasteur set up an experiment with both open and sealed flasks, thus employing a control or standard of comparison.