A rocket of mass m is launched with kinetic energy K\textsubscript{0~}from the surface of the Earth. How much less kinetic energy does the rocket have at an altitude of two Earth radii in terms of the gravitational constant, G; the mass of the Earth, m\textsubscript{E}; the radius of the Earth, R\textsubscript{E}; and the mass of the rocket? 
选项为:A:$\dfrac{GM\_{E}m}{2R\_{E}}$  B:$\dfrac{2GM\_{E}m}{3R\_{E}}$  C:$\dfrac{3GM\_{E}m}{4R\_{E}}$  D:$\dfrac{8GM\_{E}m}{9R\_{E}}$  请回答其中一个选项.