After locating a source related to a research assignment, a student should first and foremost evaluate the credibility and relevance of the source. If this option is not presented, the best choice among the given options would be to use synonyms for your search terms, as it can help broaden the search results and improve the overall quality of the research.
However, it's important to remember that simply finding a source is just the first step; critically assessing and integrating that source into your research is crucial as well.