Which Is Not a True Statement

Which is not a true statement?

A) Ultramafic rocks are commonly made by hot volcanoes in modern time
B) Most ultramafic rocks were formed when the first crust of the Earth began to form around 4 billion years ago
C) If you find a sample of komatiite in the field, you have discovered an ultramafic lava
D) If you find a sample of peridotite in the field, you have discovered an ultramafic plutonic rock that is like granite meaning it has interlocking crystals the cooled under the Earth's surface
E) Ultramafic rocks are rich in magnesium and iron and this type of igneous rock makes up most of the upper mantle but is rare in the crust