Consider the Experiment That Stanley Miller Did to Simulate Chemical

Consider the experiment that Stanley Miller did to simulate chemical evolution. Recall that a glass flask held the reduced gases NH₃, CH₄, and H₂ and that the gases were exposed to electrical sparks. What is the null hypothesis in the experiment?

A) Chemical evolution does not occur.
B) Chemical evolution requires the presence of reduced molecules.
C) Chemical evolution occurs only on Earth.
D) Chemical evolution requires a source of kinetic energy.
E) Chemical evolution requires continuous heating.