1. hydro-phobia = water-fear = the fear of water
2. hydro-ponics = water-labor = watering farm
3. water-flying = hydro-planing = Hydroplaning
4. hydro-sphere = water-ball = The water on Earth
5. hydro-electric = water-having to do with electricity = Electricity made from moving water.
Hope that helps!
The second choice is the correct one
It would probably be C but not sure