Final answer:
In Rhyolite, the minerals expected to appear as Phenocrysts are quartz and feldspar, which are common in felsic, extrusive igneous rocks like rhyolite. The correct answer to the question is a) Quartz and Feldspar. . Given the choices, a) Quartz and Feldspar is the correct answer
Step-by-step explanation:
The minerals you would expect to see as Phenocrysts in Rhyolite are quartz and feldspar. Rhyolite is a felsic, extrusive igneous rock with a chemistry and mineralogy similar to granite, but it differs in texture as it is very finely crystalline due to the rapid cooling of high-viscosity lava. This results in an aphanitic texture with crystals less than 1 mm in size.
In such felsic rocks as rhyolite or granite, you can expect to see minerals like quartz, muscovite, potassium feldspar, biotite, and plagioclase. Quartz and feldspar are key components of rhyolite and are often present as larger, visible crystals known as phenocrysts, set in a finer matrix. Given the choices, a) Quartz and Feldspar is the correct answer for the minerals expected to appear as phenocrysts in rhyolite.