Consider the triangle formed by the points O, H and G.
O is the point from which the plane started its flight. H is the location of the plane after the first 3000 meters traveled. G is the ground point right under the plane.
Therefore, we have:
[tex]\begin{gathered} \angle GOH=15\degree \\ \angle OGH=90\degree \\ OH=3000\text{ m} \\ GH=OH\cdot\sin(\angle GOH) \\ GH=3000\cdot\sin15\degree \\ GH\approx776\text{ m} \end{gathered}[/tex]
Answer: D. 776 m
