If the angular momentum of a planet of mass m, moving around the Sun in a circular orbit is L, about the center of the Sun, its areal velocity is :
(1) $4L\over m$
(2) $L\over m$
(3) $L\over2m$
(4) $2L\over m$
(1) $4L\over m$
(2) $L\over m$
(3) $L\over2m$
(4) $2L\over m$