The correct answer is: B. supercooled liquid
Glass is a non-crystalline solid. It is an amorphous solid, which means that it does not have a regular atomic structure like a crystal. Instead, the atoms in glass are arranged in a random, disordered way. This is why glass is often described as a “supercooled liquid”. It is a liquid that has been cooled so slowly that it has not had time to crystallize.
Option A is incorrect because glass is not a solid. It is an amorphous solid, which means that it does not have a regular atomic structure like a crystal.
Option C is incorrect because glass is not a gas. It is a solid.
Option D is incorrect because glass is not a superheated liquid. It is an amorphous solid.
In conclusion, the correct answer is: B. supercooled liquid.