Which of the following represents a metamorphic rock? (i) Slate (ii) Shale (iii) Quartzite A. Only (iii) B. Both (i) and (iii) C. Both (ii) and (iii) D. All (i), (ii) and (iii)

The correct answer is: B. Both (i) and (iii)

Slate and quartzite are both metamorphic rocks. Metamorphic rocks are formed when existing rocks are subjected to heat and pressure, which causes them to change their composition and texture. Slate is formed when shale is subjected to heat and pressure. Shale is a sedimentary rock that is composed of clay minerals. When shale is heated and pressurized, the clay minerals recrystallize to form slate. Quartzite is formed when sandstone is subjected to heat and pressure. Sandstone is a sedimentary rock that is composed of sand grains. When sandstone is heated and pressurized, the sand grains recrystallize to form quartzite.

Option A is incorrect because it only includes quartzite. Option C is incorrect because it only includes shale and quartzite. Option D is incorrect because it includes all three options, but only slate and quartzite are metamorphic rocks.