A successful replication of a study is __________.

A) a repetition of a study that yields the same results
B) necessary to show that the results of the first study were not merely a fluke
C) an important step in science
D) all of the above

A successful replication of a study means that the study has been repeated and obtained the same results as the original study. This is necessary to demonstrate that the results of the first study were not a fluke and are reliable. Replication is an important step in the scientific process to confirm findings and establish a foundation for future research. Therefore, all of the above options are correct.