Which of the following best describes primary data?

Primary data is defined as data that is collected specifically for a particular research purpose or objective. This means that when researchers gather primary data, they are focusing directly on their research question, and the data is tailored to provide insights relevant to that question. This direct approach allows for the collection of current and relevant information, usually through methods such as surveys, interviews, and experiments.

In contrast to the other options, which represent different forms of data or use cases, primary data stands out because it is original and specifically curated for the study at hand. For instance, data used for market trend analysis might involve both primary and secondary sources, and data collected for another study implies that the information was not originally intended for use in the current research. Similarly, data from theoretical research does not relate directly to the empirical collection of data for a specific study, as it pertains more to concepts and frameworks rather than direct investigation. Thus, the definition and purpose of primary data as data gathered for a specific purpose clearly align with the correct response.