A delivery drone uniformly slowed down from 45 m/s to 23 m/s in a straight line over a 30-minute duration within a 16-kilometer radius of its warehouse. What was the magnitude of its average acceleration?
A. 1.2 x 10^−2 m/s^2
B. 5.3 x 10^−1 m/s^2
C. 7.3 x 10^−1m/s^2
D. 4.4 x 10^1 m/s^2