A nonrotating spherical planet with no atmosphere has mass M and radius R. A projectile of mass m is launched radially from the surface of the planet with initial speed v = √GM/2R . The potential energy of the projectile-planet system, as a function of the projectile’s distance r from the center of the planet, is given by U = - GMm/r. The greatest distance from the center of the planet that the projectile reaches isA infinityB RC 7/5RD 4/3RE √2R