Extrusive igneous rocks are formed by cooling lava. Since
the temperature gradient between lava and Earth’s atmosphere is very big,
cooling is very rapid. The second option is deemed true, which also means the
third option is false. Foliations occur only in metamorphic rocks, deeming the
forth option false. Since extrusive igneous rocks are formed at the surface of
the Earth, there would be no confining pressure, which means the first option
is false.
