A 2000-Kg Truck Travelling at a Speed of 6 $\degree$ Turn in a Time of 4

A 2000-kg truck travelling at a speed of 6.0 m/s makes a 90 $\degree$ turn in a time of 4.0 s and emerges from this turn with a speed of 4.0 m/s. What is the magnitude of the average resultant force on the truck during this turn?

A) 4.0 kN
B) 5.0 kN
C) 3.6 kN
D) 6.4 kN
E) 0.67 kN