The mass of the sun is 2 × 10³⁰ kg, the mass of Mars is 6.4 × 10²³ kg, and the center-to-center distance is 2.3 × 10¹¹ m. How far from the center of the sun is the center of mass of the sun-mars system? Note that the sun's radius is 7 × 10⁸ m. a) 1.7 × 10⁹ m b) 2.3 × 10⁸ m c) 2.3 × 10⁹ m d) 1.7 × 10⁸ m