Pick out the wrong statement.

• Yellow phosphorous which is the most reactive allotropic form of phosphorous is transported under water.
• Apatite is the principal material present in phosphate rock which is chemically Ca10 (PO4)6 (F, Cl, OH).
• Urea is more hygroscopic than ammonium nitrate.
• Nitrogen fixation means the process of bringing atmospheric nitrogen into combination i.e. into nitrogen compound form.