[单选题]
If you walk 6.0 km in a straighta0 ivw 6sezk8f 6kj)u8 line in a directirobgk u7i.m* . es;4fkon north of east and you end up 2.0 km north and several kilometers east. How many degrees north of east havegb r.k7f4; .oki*esmu you walked?
A. $19^{\circ}$
B. $45^{\circ}$
C. $60^{\circ}$
D. $71^{\circ}$
