Which of the following is an example of a source of empirical evidence?

A thermometer exemplifies a source of empirical evidence because it provides direct, measurable data that can be observed and quantified. Empirical evidence is derived from observation and experimentation, and a thermometer captures specific data points regarding temperature, which can be used in scientific analysis and research.

In contrast, while a literature review summarizes existing research and findings, it does not generate new empirical data. A theoretical paper focuses on hypotheses and theoretical frameworks rather than on data collection or observations. A self-reported survey gathers subjective responses from participants, which, although valuable, reflects personal perceptions and experiences rather than objective empirical measurements like those derived from a thermometer.