First write down all the known variables:
vi = 10m/s
t = 1
a = -9.8m/s^2
vf = ?
Now choose the kinematic equation to relate these variables:
vf = vi + at
vf = (10) + (-9.8)(1)
vf = 0.2 m/s
The speed of the object travelling after a second would be 0.2m/s in reality, however, it is closest to the choice A, which would suffice as the answer for your question.
