Final answer:
Polyester, seawater, and floor are not considered minerals because they lack a crystalline structure, which is essential according to the definition of minerals.Option B is the correct answer.
Step-by-step explanation:
Polyester, seawater, and floor are not considered minerals because they lack a crystalline structure (Option B). A mineral is specifically defined as a naturally occurring, inorganic solid with a definite chemical composition and a crystalline structure.
While polyester is a synthetic polymer and thus not naturally occurring, seawater is a liquid mixture and does not have a solid crystalline structure, and a floor can be made up of various materials but typically does not have the internal atomic arrangement that would qualify it as a mineral.
It is important to note that being composed of multiple elements is not against the definition of a mineral, hence why option D is not the correct answer. In summary, the main reason they are not considered minerals is due to the absence of a crystalline structure.