A boy, who can row 6 km/hr in still water, heads directly across the current of a river flowing at the rate of 4.5 km/hr. Find the actual rate and direction of his motion.

A. 7.5 km/hr @ 53.13°

C. 4.5 km/hr 53.13°

B. 8.5 km/hr @ 54.14

D. 6.5 km/hr @ 54.14°