Final answer:
A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on repeated confirmation through observation and experimentation, not just a speculative guess. Scientific theories like that of evolution are based on a body of evidence and are reliable explanations of natural phenomena.
Step-by-step explanation:
The correct answer to the question is "C) A well-substantiated explanation of some aspect of the natural world that is based on empirical evidence and has predictive power." A scientific theory is not just a speculation or an untested hypothesis, but rather an explanation that has been reinforced by a substantial amount of scientific evidence. Theories are comprehensive and are supported by facts that have been confirmed through rigorous observation and experimentation. It's important to note that in science, the designation of 'theory' carries significant weight and is much more than a mere guess or hunch.
For example, the theory of biological evolution, the atomic theory of matter, and the germ theory of disease are all scientific theories that explain natural phenomena. These explanations are supported by evidence and have been extensively verified by the scientific community. They are not provisional ideas, but reliable accounts of the real world.
Therefore, when we refer to something as a scientific theory, we are talking about a well-established explanation that satisfactorily accounts for a body of observations and can be used to make predictions about unobserved phenomena.