Which of the following represents a tested and widely accepted model that helps explain and predict natural facts?

A theory is a well-substantiated explanation of an aspect of the natural world that is based on a body of evidence and has stood up to repeated testing and scrutiny. Theories integrate and generalize many hypotheses, providing comprehensive frameworks for understanding the underlying principles of phenomena. The strength of a scientific theory lies in its ability to predict natural facts and events based on established knowledge.

In contrast, a scientific law describes an observed phenomenon typically expressed mathematically and describes what will happen under certain conditions without explaining why it happens. A model is a simplified representation of a system or concept used to illustrate or simulate its behavior, but it may not necessarily be as comprehensive as a theory. A hypothesis is an initial, testable statement or prediction that can lead to further investigation and experimentation but lacks the extensive validation that a theory has.

Thus, a theory is the most fitting choice as it encompasses and explains a wide range of observations and facts, making it a cornerstone of scientific understanding.