When Pasteur Tested the Hypothesis of Spontaneous Generation, He Compared

Multiple Choice

When Pasteur tested the hypothesis of spontaneous generation, he compared the ability of a sterilized growth medium (meat broth) to produce a population of bacteria in two different types of flasks. One had a simple neck open to the outside, and the other had a "goose neck bend that also was open to the environment. Pasteur expected that bacteria would appear in the flask with the standard neck. In this experiment, the standard neck flask served as:

A) an observation.
B) a variable.
C) a control.
D) a statistic.
E) a hypothesis.