An Aeroplane flies 400 m north and 300 m south and then flies 1200 m upwards then net displacement is

An Aeroplane flies 400 m north and 300 m south so the net displacement is 100 m towards north.

Then it flies 1200 m upward so $r=\sqrt{{100}^2+{1200}^2}=1204\cong 1200m$

The option should be 1204 m, because this value mislead one into thinking that net displacement is in upward direction only.