A aeroplane is flying horizontally with speed of 432 km/hr at height h meter from ground. Its angle of elevation from a point on ground is 60°. After 20 sec its angle of elevation from same point is 30° then the height 'h' is equal to
\(A) 1200\sqrt3\)
\(B) 600\sqrt3\)
\(C) 1800\sqrt3\)
\(D) 1000\sqrt3\)