A person running down the hallway at a velocity of 4.2 m/s comes to a stop in a time of 1.8 seconds to avoid hitting the wall. What was the acceleration of the person?
A.) 7.6 m/s/s
B.) -7.6 m/s/s
C.) 2.3 m/s/s
D.) -2.3 m/s/s