Which of the following options helps identify resources for online research?

Identifying resources for online research can greatly benefit from the use of a Boolean search method, which allows researchers to refine their searches using specific logical operators like AND, OR, and NOT. This method enables an individual to narrow down or broaden search results depending on their research needs. For example, using "AND" between terms can help in finding sources that contain all specified terms, while "OR" can help to locate articles containing either of the terms, which is particularly useful when dealing with synonyms or related concepts. Thus, it is a strategic approach that enhances the effectiveness of online searches by facilitating a more targeted retrieval of information.

The other options, while useful in certain contexts, do not directly assist in the process of identifying resources for online research. A library catalog system is primarily focused on organizing physical and digital materials rather than enhancing search effectiveness through logical operations. An email communication tool facilitates correspondence, which does not pertain to resource identification. A digital content management system is used for organizing and managing digital content, but it does not inherently improve search strategies like Boolean logic does.