[单选题]
2. Which of the following p 9l osvtb2 jrxecsq -.m0+wl66g5e;tare functi/gx lent ,xn3)d5 aw8hons of the cerebellum?
I. Coordination of skeletal muscle contraction.
II. Voluntary movement of the limbs.
III. Maintenance of balance.
IV. Perception of pain.
A. All of the above.
B. I and III only.
C. II and IV only.
D. I only