A 13 m ladder leans against a vertical wall. The foot of the ladder slides away from the wall at 2 m/s. When the foot is 5 m from the wall, what is the rate of change (in rad/s) of the angle θ between the ladder and the ground?
a) 1.7×10−1
b) −1.7×10−1
c) −1.5×10−1
d) −8.3×10−2