The correct answer is C. chemically unreactive.
Inert gases are elements in group 18 of the periodic table. They are also called noble gases or rare gases. They are monatomic gases at standard temperature and pressure and have very low chemical reactivity. They are not miscible with water and are chemically unreactive.
Option A is incorrect because inert gases are not miscible with water. They are nonpolar molecules and do not form hydrogen bonds with water molecules.
Option B is incorrect because inert gases are stable. They have full valence shells and do not need to gain or lose electrons to form stable compounds.
Option D is incorrect because inert gases are chemically unreactive. They do not form compounds with other elements easily.