Which answer can be used to illustrate the law of multiple proportions?
naf, nabr
hci, ci2
so, so2
co2, h2co3
ch4, co2

SO and SO2

Explanation:

Law of multiple proportion states that when two elements combine with each other to form a compound, the mass of one element that combines with a fixed mass of the other element are always in ratio of whole numbers.

Here the elements that combine are sulfur and oxygen. Oxygen combines with a fixed mass of sulfur,i.e. 32 g( molar mass of sulfur is 32 g / mole).the mass of oxygen that combines with 32 g of sulfur in SO and SO2 is 16 g and 32 g(molar mass of oxygen is 16 g).

The ratio of  mass of oxygen  in SO and SO2 is

16:32

= 1:2.

This is accordance with law of multiple proportion.

a corroding iron, if that's one of your choices