A. Divide the change in the objects velocity by the time it takes to make that change.
Explanation:
Acceleration is a vector quantity whose magnitude is given by the following equation:
\(a=\frac{\Delta v}{\Delta t}\)
where
\(\Delta v\) is the change in velocity of the object
\(\Delta t\) is the time it took to make the change in velocity
Therefore, we see that this equation corresponds to choice A.
