To project a body of mass $$m$$ from earth's surface to infinity, the required kinetic energy is (assume, the radius of earth is $$R_E$$, $$g =$$ acceleration due to gravity on the surface of earth):

A

$$2mgR_E$$

B

$$4mgR_E$$

C

$$mgR_E$$

D

$$\frac{1}{2}mgR_E$$