The correct answer to how sedimentary rocks are formed, based on common geological processes, is:
A.) sand is compacted and cemented together.
Sedimentary rocks typically form through the accumulation and compaction of sediments, which can include particles from other rocks, minerals, and organic material. Choices B, C, and D describe the formation of different types of rocks (organic material for coal, metamorphic processes, and igneous processes, respectively).