Neil is comparing the shifts in light patterns of two distant galaxies. Using a powerful telescope, he records the light shifts of each galaxy every 20 seconds (s) for six hours (hr). After sharing his data with Betty, another astronomer, she says that this is not an experiment. Which of the following statements supports Betty's claim? A This is not an experiment because there are too many variables. B. This is not an experiment because no variables are manipulated. C. This is not an experiment because it uses only theoretical predictions. D. This is not an experiment because astronomers are not considered research scientists.