Question

Magma that cools and crystallizes on Earth's surface forms 

A. quartz.  
B. marble.   
C. intrusive rocks.   
D. extrusive rocks.

Answer 1

The answer is D. Extrusive igneous rocks form when magma reaches the Earth's surface a volcano and cools down very quickly. This forms many small crystal on the rock.

Answer 2

The correct answer is:

D. Extrusive rocks.

The explanation:

when extrusive igneous rocks form when magma reaches the Earth's surface a volcano and cools quickly. Most extrusive (volcanic) rocks have small crystals. Examples include basalt, rhyolite, andesite, and obsidian.