Your teacher didn't put any xy axis on this grid. But I'm assuming that the vectors are coming from the origin (0,0)
If that is the case, then vector v = (-2,4) and vector u = (2,1)
Add the corresponding coordinates to get
v+u = (-2,4)+(2,1) = (-2+2,1+4) = (0,5)
The answer is therefore choice B
The general rule for adding vectors is
if u = (a,b) and v = (c,d), then u+v = (a+c, b+d)