A student places seedlings in four separate test-tubes. Tube W has all the mineral ions required for healthy plant growth. The remaining three tubes contain water, all minerals except magnesium ions, and all minerals except nitrates. The diagram shows how these seedlings look after two weeks. What are the contents of tubes X, Y and Z?
- AX: all minerals except magnesium ions; Y: all minerals except nitrates; Z: water
- BX: all minerals except magnesium ions; Y: water; Z: all minerals except nitrates
- CX: all minerals except nitrates; Y: all minerals except magnesium ions; Z: water
- DX: water; Y: all minerals except magnesium ions; Z: all minerals except nitrates