Pulling Out of a Dive,the Pilot of an Airplane Guides

Multiple Choice

Pulling out of a dive,the pilot of an airplane guides his plane into a vertical circle.At the bottom of the dive,the speed of the airplane is 320 m/s.What is the smallest radius allowable for the vertical circle if the pilot's apparent weight is not to exceed 7.0 times his true weight?

A) 1700 m
B) 1500 m
C) 2200 m
D) 230 m
E) 42 m