A new planet is discovered orbiting a single star. The planet has one moon. According to Kepler's first law, what do scientist know about the orbit of the planet around the star?
A. The orbit is circular with the star at the center of the circle.
B. The orbit is elliptical with the star at one focus of the ellipse
C. The planet takes 12 times longer to orbit the star than the moon takes to orbit the planet
D. The planet orbits the star in a direction opposite to the direction of the moon's orbit of the planet