Which of these discoveries is generally attributed to kepler?

The question is incomplete and no options are given but the answer is;
The orbit of Mars is an ellipse, is generally attributed to Kepler.
Kepler's first law states that; "The orbits of the planets are ellipses, with the Sun at one focus of the ellipse.
The planet at that point takes after and follow the ellipse in its orbit, which implies that the distance between Earth and Sun remove is continually changing as the planet goes around its orbit.