What determines weather a metamorphic rock is foliated of non-foliated?

the presence of absence of mineral crystals

the number of remaining gas molecules

temperature, pressure, and the original type of rock.

the water content as a percentage of the rock volume.

(C) Temperature, pressure, and the original type of rock.

Explanation:

Option (3)

Explanation:

Metamorphic rocks are usually defined as those rocks that are obtained from the previously existed sedimentary, igneous, or other metamorphic rock due to the influence of high temperature and pressure conditions. For example, Quartzite, Schist, and Gneiss.

These rocks are found to be foliated as well as non-foliated, which directly depends upon the temperature, pressure condition, and the original rock type.

The foliated metamorphic rocks are formed when the temperature is comparatively low but the pressure is extremely high and is unequal. For example, Schist and Gneiss.

On the other hand, the non-foliated metamorphic rocks are formed when the temperature is high but has relatively low pressure. For example, Quartzite.

Thus, the correct answer is option (3).