Planet Roton Has a Mass of 4

Multiple Choice

Planet Roton has a mass of 4.0 × 1023 kg and a radius of 2.0 × 106 m. With what speed should a space probe be launched from the surface of Roton so as to achieve a maximum distance of 3.0 × 106 m from the center of Roton?

A) 4.2 km/s
B) 3.9 km/s
C) 3.0 km/s
D) 3.4 km/s
E) 6.0 km/s