A body is projected vertically upwards from the surface of a planet of radius ( r ) with a velocity equal to ( 1/3 ) the escape velocity for the planet. The maximum height attained by the body is:
a) ( 1/3 ) of the radius of the planet
b) ( 2/3 ) of the radius of the planet
c) Equal to the radius of the planet
d) ( 3 ) times the radius of the planet
