What is a fact?

A fact is defined as a provable statement that can be shown to be true without any doubt. This means that a fact is based on objective reality and can be verified through evidence, observation, or reliable sources. For instance, the statement "Water boils at 100 degrees Celsius at sea level" can be tested and proven true, making it a fact. The essence of a fact lies in its truth value being independent of personal beliefs or opinions, thus allowing it to remain unchanged regardless of individual perspectives.

In contrast, the other choices involve statements that are either subjective or not definitively provable. Statements supported by good reasons may lean towards being accepted as true, but they do not reach the level of certainty that qualifies as a fact. Likewise, personal beliefs or feelings are inherently subjective and cannot be objectively verified, disqualifying them from being considered facts.