The correct answer is D. All of the above.
The type of igneous rock that forms from magma is a function of the chemical composition of the magma, the temperature of solidification, and the rate of cooling.
The chemical composition of the magma determines the types of minerals that will crystallize from it. The temperature of solidification affects the size of the crystals that form. The rate of cooling affects the type of crystals that form.
If the magma cools slowly, large crystals will form. If the magma cools quickly, small crystals will form. The type of crystals that form also affects the physical properties of the igneous rock.
For example, granite is an igneous rock that forms from magma with a high silica content. Granite cools slowly, so large crystals form. These large crystals give granite its characteristic appearance.
Basalt is an igneous rock that forms from magma with a low silica content. Basalt cools quickly, so small crystals form. These small crystals give basalt its characteristic appearance.
The rate of cooling also affects the texture of the igneous rock. If the magma cools slowly, the crystals will have time to grow large and the rock will have a coarse texture. If the magma cools quickly, the crystals will not have time to grow large and the rock will have a fine texture.
The type of igneous rock that forms from magma is also affected by the pressure at which the magma cools. If the magma cools at high pressure, the crystals will be forced to grow in a specific orientation. This orientation can be seen in the rock’s texture.
The type of igneous rock that forms from magma is a complex process that is affected by many factors. The chemical composition of the magma, the temperature of solidification, the rate of cooling, and the pressure at which the magma cools all play a role in determining the type of igneous rock that forms.