Which best explains why replicating an experiment should be done by someone other than the person who originally did the experiment? it shows that the results are the same using different methods. it shows that the experiment is easy to do. it shows that the results are as expected. it shows that the experiment is designed properly.

The correct answer is It shows that the experiment is designed properly.

Repeating the experiment by other scientists is important thing because that’s the way to approve the experiment design and result. Scientists repeat others' experiments to verify the accuracy of the findings (peer review)  and also  to refine the results or simplify the methodology.

The answer's d: it shows that the experiment is designed properly. Because when it's designed properly, anyone should be able to do it and get the same results.