All of the given options can happen to a sedimentary rock as it metamorphoses to become a metamorphic rock.
A. Minerals present may change: During the process of metamorphism, the minerals present in the sedimentary rock can undergo chemical changes. New minerals may form, while others may recrystallize or transform into different mineral compositions due to the increased temperature and pressure.
B. Rock texture may change: Metamorphism can cause significant changes in the texture of the rock. The original sedimentary rock, which typically has a layered or fragmentary texture, can be transformed into a more uniform and interlocking texture characteristic of metamorphic rocks. This change in texture is often associated with the rearrangement and growth of mineral crystals.
C. Crystals of minerals may become larger with higher-grade metamorphism: As the intensity of metamorphism increases, such as with higher temperatures and pressures, the mineral crystals in the rock can grow in size. This process is known as recrystallization, where existing minerals dissolve and reform as larger crystals. Therefore, with higher-grade metamorphism, the crystals in the metamorphic rock may become larger and more distinct.
It's important to note that the specific changes experienced by a sedimentary rock during metamorphism can vary depending on factors such as the original composition of the sedimentary rock, the intensity of metamorphic conditions, and the duration of metamorphic processes.