The correct answer is $\boxed{\text{B}}$, Argon.
Group 17 of the periodic table is the halogen group. The halogens are highly reactive non-metals that are found in nature as diatomic molecules. They are all highly electronegative and form strong bonds with metals. The halogens are also very good oxidizing agents.
Chlorine is a greenish-yellow gas at room temperature. It is the most abundant halogen in the Earth’s atmosphere. Chlorine is used in a variety of industrial processes, including the production of bleach, PVC, and pharmaceuticals.
Fluorine is a pale yellow gas at room temperature. It is the most reactive element in the periodic table. Fluorine is used in the production of hydrofluoric acid, which is used in the etching of glass and metals.
Bromine is a reddish-brown liquid at room temperature. It is the only non-metallic element that is liquid at room temperature. Bromine is used in the production of flame retardants, dyes, and pharmaceuticals.
Argon is a colorless, odorless, and tasteless gas at room temperature. It is the third most abundant element in the Earth’s atmosphere. Argon is used in light bulbs, lasers, and welding.
Argon does not belong to group 17 because it is a noble gas. Noble gases are elements that are very stable and do not react with other elements. They are all gases at room temperature and have very low boiling points.