Answer: Option (D)
Step-by-step explanation: The works of different scientist varies from one another. An astronomer deals with the study of the space including the galaxies and the entire solar system, whereas a biologist studies the about the different lives that exist on earth, their anatomy and the internal structure, and many more.
This scientists working at different fields, after doing research, obtains a certain sets of data that are different from one another. This is the reason why they give a different conclusion working with different different data set.
Thus, the correct answer is option (D).