[单选题]
In its lowest quantum sthvs4b)7 m5 fk(dd)e3 ;dgnfk rate, a diatomic quantum mechanical rotator has a rotatisy mj jghadf 0:;4.ag;.i g;mional eij:sha f gim;yg;.g d.jam0 ;4nergy of
A. zero.
B. $h/2 \pi I$.
C. $h/\pi I$.
D. none of the given answers
