The existence of a substance in more than one solid modifications is known as :
The correct option is B Polymorphism
The existence of a substance in more than one solid modifications is known as polymorphism. It is the ability of a solid material to exist in more than one form or crystal structure. Polymorphism can potentially be found in any crystalline material including polymers, minerals, and metals, and is related to allotropy, which refers to chemical elements.