In scientific terms, what distinguishes a theory such as the theory of evolution?

• A. A theory is a well-substantiated explanation of some aspect of the natural world, based on a body of evidence.
• B. A theory is a mathematical formula used to describe natural phenomena.
• C. A theory is any idea that has been widely accepted by scientists.
• D. A theory is a guess or hypothesis that scientists have yet to prove.

Answer: (A)