Explanation:

- Let the ship's deck be at height \( h \) above the water.

- Angle of elevation to tower's top is 60°.

- Angle of depression to tower's base is 30°.

- For the top, use tan(60°) = height of top part above the ship / distance to the tower.

- For the base, use tan(30°) = height of the ship / distance to the tower.

- Both angles create two equations with the same horizontal distance.

- Solving gives the tower's height as 4h.

- Option:1 is 2h.

- Option:2 is 3h.

- Option:3 is 4h.

- Option:4 is 5h.