A balloon is moving up in air vertically above a point A on the ground. When it is at a height `h_1`, a girl standing at a distance (point B) from A (see figure) sees it at an angle `45^@` with respect to the vertical. When the balloon climbs up a further height `h_2`, it is seen at an angle `60^@` 2with respect to the vertical if the girl moves further by a distance 2.464d (point C). Then the height `h_2` is (give `tan 30^@ = 0.5774`)

Options

A. 1.464 d
B. 0.732d
C. 0.464d
D. d