23) E

The order is clearly given by the paragraph.

The third sentence says that in the presence of air, the last water molecule is displaced by oxygen.

So water is weaker than oxygen.

In the last sentence, it says that in the presence of carbon monoxide, oxygen is displaced. So oxygen is weaker than carbon monoxide. Therefore, water must also be weaker than carbon monoxide.

We get the order:

water, oxygen, carbon monoxide.