Tom tells Greta that his father, an astronomer, is planning a scientific experiment to study another galaxy. Using a powerful telescope, Tom's father will record data of shifts in light patterns every 30 seconds.
He will later study the data. Greta says that this is not an experiment. Which of these statements
supports Greta's statement?

A. This is not an experiment because it is not performed in a lab.

B. This is not an experiment because there are too many variables.

C. This is not an experiment because a variable cannot be manipulated.

D. This is not an experiment because it uses only theoretical predictions.