What does the term "phenomenon" refer to?

The term "phenomenon" refers specifically to any fact or event that can be observed and documented. This meaning emphasizes the importance of empirical evidence and objective observation in understanding the subject at hand. Phenomena can range from natural occurrences, such as weather patterns, to social behaviors that can be recorded and analyzed.

The other options do not align with this definition. A theoretical concept that is untestable falls outside the realm of observable facts, while an opinion that can be debated lacks the objectivity and verifiability associated with a phenomenon. Similarly, a common myth without evidence does not qualify as a phenomenon because it is not based on observable facts or documented events. Thus, the correct option accurately captures the essence of what defines a "phenomenon."