Magnesium in octahedral sheet of clay mineral indicates

Answer: Option B

Clay minerals are hydrous aluminum phyllosilicates, sometimes with variable amounts of iron, magnesium, alkali metals and alkaline earth.
Clay minerals form in the presence of water, and have been important to life. Clay minerals are characterized by two-dimensional sheets of corner-sharing SiO₄ tetrahedra or AlO₄ octahedra.
Magnesium is an octahedral sheet of clay mineral that indicates Trioctahedral.