Pulling Out of a Dive, the Pilot of an Airplane

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 7.00 times his true weight?

A) 1740 m
B) 1490 m
C) 2240 m
D) 228 m
E) 41.7 m