Context: This is a piece of quartzite. Quartzite forms when sandstone is changed by high temperature and pressure.
Quartzite is made mostly of the mineral quartz. It can also contain small amounts of other minerals. Depending on the minerals it contains, a piece of quartzite can be white, gray, pink, red, green, or blue.
What type of rock is quartzite?
A. igneous
B. metamorphic
C. sedimentary
Answer with the option's letter from the given choices directly.

B