vo=0
d1=vo*t1+a*t1^2/2=0+1*20^2/2=0,5*400=200 m=>d1=200 m
v1^2=vo^2+2a*d1=0+2*1*200=400=>v1=20 m/s
t2=10 min=600 s
d2=v1*t2=20*600=12000 m=>d2=12000 m
vf=0
vf^2=v1^2-2af*d3<=>0=20^2-2*0,5d3<=>400=d3=>d3=400 m
D=d1+d2+d3=200+400+12000=12600 m=>D=12600 m->c)