De'Andre is researching whether coffee drinking affects academic performance for a class project. Based on his understanding of effective research engine search strategies, he searches for "coffee academic performance" on the library's search engine, which results in over $500,000$ results. What should De'Andre do next?

a$.$ Alter his search by adding modifiers, filters, or search criteria.

b$.$ Use a similar search on other engines $($e$.$g$.,$ Google Scholar$).$

c$.$ Start reading each source to determine its utility to his project.

d$.$ Alter his search by removing one of the three words in his original search.