A boat is traveling east across a river that is 112 meters wide at 8 meters per second. If the river has a northward current of 5 meters per second, what is the resultant speed of the motorboat rounded to the nearest tenth?

A) 3.0 m/s

B) 9.4 m/s

C) 8.6 m/s

D) 13.0 m/s