Which of the following is included in organic matter?

Organic matter is composed primarily of carbon-based compounds that originate from the biological processes of living organisms. This includes the remains of plants and animals, as well as decomposed organic materials such as leaves, grass, and other biological residues. Humans, being a part of the biological ecosystem, also contribute to organic matter through their waste and remains.

In contrast, options such as sand and minerals are primarily inorganic materials. Sand is composed of small rock and mineral particles and does not have any biological origin. Similarly, minerals are naturally occurring inorganic substances that do not derive from the breakdown or decomposition of living organisms. Therefore, the presence of plants, animals, and humans as components of organic matter clearly makes this choice the most accurate.