What is usually a common limitation of qualitative research?

Qualitative research often involves in-depth exploration of topics, which can lead to rich and detailed insights. However, this depth can also result in significant time investments, as conducting interviews, focus groups, or observations requires meticulous planning and execution. Additionally, the subjective nature of qualitative research means that researchers must interpret data, which can introduce personal biases and vary based on different researchers' perspectives. This combination of time consumption and subjectivity presents a common limitation, making option B the most accurate choice.

While the other options present valid points about qualitative research, they do not capture this particular limitation as effectively. For instance, qualitative research can indeed be grounded in theoretical frameworks, relying on established theories to guide the research process. Furthermore, while it relies primarily on qualitative data, this is not inherently a limitation; rather, it's a distinguishing feature of such research. As for reliability, comparing qualitative and quantitative research involves different methodologies and standards of reliability, and qualitative research can be reliable when conducted rigorously, even if it may not adhere to the same statistical measures as quantitative research.