What best characterizes a theory in the field of science?

A theory in the field of science is best characterized as a synthesis of a large body of well-tested knowledge. This definition underscores that a theory is not simply a guess or an assumption; rather, it is a well-established explanation that has been rigorously tested through experimentation and observation. Theories integrate and unify various facts and hypotheses that have been validated over time, making them robust frameworks for understanding specific natural phenomena.

Scientific theories are developed after a significant amount of empirical evidence has been gathered, demonstrating their reliability and applicability across different scenarios. For example, the theory of evolution or the theory of relativity both represent comprehensive understandings of their respective fields, grounded in extensive research and extensive corroborating data.

In contrast, an unproven hypothesis, a mere guess, or a collection of random observations do not provide the same level of substantiation and coherence that characterizes a scientific theory. These alternatives lack the depth of verification and integration that a theory embodies, making it clear why the correct answer highlights the importance of tested knowledge in defining what a theory is.