Louis Pasteur's experiments disproving spontaneous generation were different from John Needham's in which important way?

A) The necks of the flasks Pasteur used were bent into an S-shape and left open to the air.
B) Pasteur boiled infusions to kill any microbes present.
C) The necks of Pasteur's flasks were bent into an S-shape and then melted to seal them.
D) Pasteur used meat broths instead of infusions.
E) The flasks Pasteur used were sealed with corks.