To Measure the Mass of a Planet with the Same

Multiple Choice

To measure the mass of a planet with the same radius as Earth, an astronaut drops an object from rest (relative to the planet) from an altitude of one radius above the surface.When the object hits its speed is 4 times what it would be if the same experiment were carried out for Earth.In units of M_E (the mass of the Earth) , the mass of the planet is:

A) 2 M_E
B) 4 M_E
C) 8 M_E
D) 16 M_E
E) 32 M_E