Answer:
The correct option is;
C. Repeating an experiment to verify results
Step-by-step explanation:
A scientific theory is a statement explaining an observed natural phenomenon which can be simulated for verification ensuring that all protocols of the scientific method of investigation are observed.
By repeating the experiment under particular conditions such as through verification of data from direct observation such as in astronomy, a scientific theory can be improved by pointing out the natural behavior of the phenomenon to better clarify the assumptions made in the theory.