[单选题]
The driver of a motorboat that can move at 10 m/s in *vmhi. .:rpl q njrzhb7y; 19mstill water wishes to e npayxeo1; :je5x 7a.travel directly across a narrow strait in which the cur.1: oxjxane5 ;7epye arent flows at 5.0 m/s. At what angle upstream should the driver head the boat?
A. $27^{\circ}$
B. $30^{\circ}$
C. $60^{\circ}$
D. $63^{\circ}$
