When the chronometer marks 5.6 s, a small sphere is thrown vertically upwards from the top of a building with an initial velocity of 8 m/s and reaches the ground when the chronometer marks 12.2 s. Considering that only gravity acts, g=10 m/s2. Which of the following statements is correct for a certain reference system?
I. While going up, the motion equation is y=8t-5t2 and while going down: y=8t+5t2.
II. Throughout the motion, the velocity is V=8-10t.
III. The position is: y=165+8t-5t2.

a) Only I
b) I and II
c) Only II
d) Only III
e) II and III