In scientific inquiry, how is a theory best defined?

A theory is best defined as a hypothesis that has been extensively tested and accepted by the scientific community. This definition is rooted in the rigorous process of scientific inquiry, where a hypothesis is not merely a guess or an untested assumption but is based on empirical evidence gathered through experimentation and observation.

Over time, when a hypothesis withstands repeated testing and is consistently supported by observations across various scientific disciplines, it gains acceptance within the scientific community. This level of validation provides a robust framework for understanding certain phenomena and can be used to predict outcomes in future experiments. A well-established theory integrates and synthesizes a wide range of facts and findings, enabling a deeper understanding of complex relationships in nature.

In contrast, options that suggest a theory is a single untested hypothesis or is merely a guess do not accurately reflect the established understanding of scientific theory. A true scientific theory requires extensive supporting evidence and consensus among scientists, distinguishing it from more speculative ideas or initial hypotheses that may not have yet undergone thorough testing.