Chemistry · Allotropes of Carbon

When an element exists in two or more different forms in the same physical state, these forms are called allotropes, and the phenomenon is known as allotropy. Allotropes have similar chemical properties but differ in their physical properties. Substance X is a moderate conductor of electricity and has a hexagonal layered structure. Which statements about substance X are correct? I. It is a covalent substance. II. It has a giant molecular structure. III. It has the same structure as graphite. IV. It has the same structure as diamond.