a. reviewing the literature of existing theories produces similar results.
Explanation:
Replication refers to the repetition of a research study, or literature review usually with various circumstances and topics, in order to decide if the basic results of the initial study can be generalized to other respondents and situations. When replicating experiments, and obtaining the same results as the actual study , the results are given greater validity. If an investigator is able to reproduce the findings of a study it indicates that it is more likely to generalize the results to the wider population.