What is the average acceleration of a jet ski that goes from rest to 10 m/s west in 4 s? Take the direction west to be positive, and east to be negative.

A.
2.5 m/s2

B.
-2.5 m/s2

C.
0.4 m/s2

D.
-0.4 m/s2
whats the answer i need help please