The correct answer is B. Tellurium.
Halogens are a group of chemical elements in the periodic table that are highly reactive and form salts with metals. They are all non-metals and have seven valence electrons. The halogens are fluorine, chlorine, bromine, iodine, and astatine.
Tellurium is a metalloid in the periodic table. It is not a halogen because it does not have seven valence electrons. Tellurium has 4 valence electrons.
Fluorine is the most reactive element in the periodic table. It is a pale yellow gas that is very poisonous. Chlorine is a greenish-yellow gas that is also poisonous. Bromine is a red-brown liquid that is also poisonous. Iodine is a purple solid that is less poisonous than the other halogens. Astatine is a radioactive element that is very rare.