What is defined as truths that can be proven?

The correct choice identifies "facts" as truths that can be proven. Facts are statements that can be verified through observation, measurement, or evidence. They are objective and remain consistent regardless of personal beliefs or interpretations. For example, water boils at 100 degrees Celsius under standard atmospheric pressure; this statement can be proven through scientific measurement.

On the other hand, assertions are claims that may or may not be true and do not necessarily require evidence. Opinions are personal beliefs or judgments that may vary from person to person and cannot be proven true or false. Theories are well-substantiated explanations based on a body of evidence but still require testing and validation; they are not absolute truths. Therefore, "facts" stands out as the answer that accurately captures the definition of proven truths.