Top-soil contains the following
(a) Humus and living organisms only
(b) Humus and soil particles only
(c) Humus, living organisms and plants
(d) Humus, living organisms and soil particles.
(d) Humus, living organisms, and soil particles.
The topmost layer of the soil that contains humus and living organisms in addition to the soil particles. Topsoil is a thin layer and contains soil's nutrients.