What couse the rusting in metals?

The rusting of metals occurs when iron, oxygen, and water combine.When they combine, the iron loses electrons to oxygen atoms. This is called oxidation and when it happens it produces a chemical reaction forming Fe203 Iron Oxide otherwise known as Ferric Oxide, or more commonly known as rust.

what are the óptions. pléase list them

93.2 ml + 3920 ml = 4013 ml total  

(93.2 ml) * (2.03 m) / (4013 ml) = 0.0471 m

the volume in in l of the diluted solution would be 0.0471 m.