choose the correct answer and why?

a car starts from rest and reaches speed of 80 km/h in 16 s
the average acceleration of the car is:
a\ 0.7 m/s*2
b\1.4 m/s*2
c\5 m/s*2

Speed = 80km/h = 80000m/3600s = 22.22m/s

a = (V-Vo)/t = (22.22-0)/16 = 1.4 m/s^2.