What kind of research could include commentaries and histories?

The correct answer is secondary research, which involves the analysis and interpretation of information that has already been collected and published by others. This type of research typically includes commentaries and histories, as researchers synthesize existing data and perspectives to draw conclusions or highlight trends within a particular field.

In contrast, primary research involves gathering new data firsthand, such as conducting experiments or surveys, thus would not typically feature commentaries and histories. Qualitative research focuses on understanding subjective experiences and meanings through methods such as interviews or observations, often yielding rich narrative data, but it does not inherently include pre-existing commentaries or historical analysis. Tertiary research, on the other hand, compiles and summarizes information from primary and secondary sources and might include bibliographies or factbooks, but it does not focus on in-depth commentary or historical context. Therefore, secondary research is the most fitting choice as it actively engages with previously published commentary and historical documentation for understanding and analysis.