Answer:
The answer to this question is sedimentary rock.
Step-by-step explanation:
Sediments are gathered together on, let's say the ocean floor. These pieces of shell, fossils, debris, etc, will slowly compact into each other, and over the course of many years, they will stick together, forming layers of sediment. Over some more time, there will be enough layers for the item to finally be considered a sedimentary rock.
Hope this helped!