The Contradictory Results Obtained by Different Scientists Apparently Doing the Same

The contradictory results obtained by different scientists apparently doing the same experiments in investigating spontaneous generation

A) show that experiments should only be done once.
B) show the importance of exactly duplicating experimental conditions.
C) led to further experiments that ultimately proved spontaneous generation.
D) could not be explained by anyone involved in the work.
E) led to the development of swan-necked flasks.