One of the most well-known theories in physics is Newton's theory of gravity. Select the statements that are true of Newton's theory. A. Newton's theory was his best guess for why an apple fell out of a tree. B. Newton's explanation of gravity became a theory after repeated rigorous tests confirmed that it was true. C. Newton's theories have been modified as new information is discovered. D. Newton's theory has been shown to be true and is thus no longer open to experimentation