Which best describes a theory?
a. a well-supported conclusion
b. a proven fact
c. an educated guess
d. an untested claim

A. a well-supported conclusion

Explanation:

A theory can be define as the explanation for the cause of the natural phenomena or event, believes based upon the results obtain after the experimental procedures. A scientific methodology is required to be followed in order to prove that the theory is valid. The steps of the scientific methodology includes observation, making an hypothesis, making a prediction, testing prediction by experimentation, analysis of data and conclusion. A theory should be conclusive to be accepted by the scientific society unless arguments or negative claims may arise.