Answer :
(d) Porphyritic texture of igneous rock textures is characterized by distinct sizes of minerals.
In these rocks, larger crystals, known as phenocrysts, are embedded in a finer-grained matrix called the groundmass. This texture indicates that the rock has undergone a two-stage cooling process. Initially, the larger crystals cool slowly deep below the Earth’s surface, allowing them to grow bigger. Later, the magma rises to a shallower depth or even to the surface, cooling more rapidly and forming the finer-grained matrix.
