Final answer:
Rhyolite is the correct answer. It is a felsic, extrusive igneous rock composed of 70% SiO2 and characterized by its color, texture, and mineral content.
Step-by-step explanation:
The correct answer is b) Rhyolite.
Rhyolite is a felsic, extrusive igneous rock that is composed of 70% SiO2. It is characterized by being light gray to pinkish to somewhat reddish in color. Rhyolite has an aphanitic texture with crystals less than 1 mm in size.
In terms of mineral content, rhyolite typically contains quartz, muscovite, potassium feldspar, and Na-rich plagioclase, along with possibly a little biotite.
These minerals give rhyolite its characteristic composition and appearance.