Ships are constructed from steel, which is an alloy of iron. Blocks of magnesium are fixed to the underside of ships so that rusting does not occur. Which statement describes how the magnesium prevents rusting?
- AMagnesium oxidises instead of iron.
- BMagnesium stops air and water getting to the iron.
- CThe magnesium forms an alloy with iron which does not corrode.
- DThe magnesium reacts with rust as soon as it is formed.