Answer the following question given this paragraph: 

Soil is a mixture of eroded rock, minerals, partly decomposed organic matter, and other materials. It is essential for plant growth, so it is the foundation of terrestrial ecosystems. Soil is important for other reasons as well. For example, it removes toxins from water and breaks down wastes.


Q: What is a mixture of eroded rock, minerals, partly decomposed organic matter, and other materials called?

 Choices:

- loam

- sand

- sediment

- soil

A:
soil
