Carbon Monoxide Law Carbon Monoxide?

Carbon monoxide? - carbon monoxide law

Treatment of poisoning by carbon monoxide can be done using pure oxygen to breathe, it is an example of ______ for use in a clinical setting.

1. Conservation of mass
2. The principle of Le Chatelier
3. ideal gas law
4. Henry's Law
5. Precipitation

I've got Henry's law or the principle of Le Chatelier.
the longer the Henry's law?
What is Henry's law, is not it?
I looked at Wikipedia, but I do not understnad what that means.
Thank you!