## The distance of the horizon at the sea varies as the square root of the height of the eye above sea level. When the distance is 14.4 km, the height of the eye is 18 metres. Find, in kilometres, the distance when the height of the eye is 8 metres.

- A. 4.8 km
- B. 7.2 km
- C. 9.6 km
- D. 12 km