[单选题]
07.08: What does one ob;vldh4 62kfjwq)zh; uqh0 b6 ptain by dividing the distance of -*4u: vguo:j4hnob2aryg lu x*(4 f ss12 Mm by the time of 4 Tsjfls:un4o*24(xgh ys o-uu: *gr 4b va?
A. $3 \; nm/s$
B. $3 \; \mu m/s$
C. $3 \; mm/s$
D. $3 \; km/s$
E. $3 \; Gm/s$