D). Many different experiments are performed and repeated.
This is false. Absolute brightness is the term used to describe how bright a star would look if it were a standard distance from Earth. Apparent brightness is how bright it would look as far as it currently is from Earth. Hope this was helpful!
The reason both of these are valid scientific hypotheses is because A) scientists with different educational backgrounds may put forth different hypotheses to explain the same data.
This approach in science is vital in making progress and has helped to explain many phenomena in the past. When scientists explain data using different approaches, they come to a more comprehensive conclusion.
