Final answer:
Extrusive igneous rocks are fine-grained because they cool quickly on the Earth's surface, not slowly beneath it. The statement in the question is false.
Step-by-step explanation:
The statement that extrusive igneous rocks are typically fine-grained because they crystallized slowly deep below the Earth's surface is False. In fact, extrusive igneous rocks, also known as volcanic rocks, cool quickly on or near the Earth's surface, leading to the formation of very small or even no visible crystals, giving them a fine-grained texture. In contrast, intrusive igneous rocks, such as granite, are formed from magma that cools slowly beneath the Earth's surface, which allows time for the development of large, visible crystals, resulting in a coarse-grained texture.
Basalt is an example of an extrusive igneous rock with fine grains, while granite is an example of an intrusive rock with coarse grains.