In a Temperate Region, the Most Distinctive Feature of the O

Multiple Choice

In a temperate region, the most distinctive feature of the O horizon of a soil is:

A) its inability to maintain fertility because of constant leaching of materials to lower soil horizons.
B) the mixture of mostly inorganic matter and humus.
C) the abundance of finely ground rock particles.
D) the abundance of both organic matter and living organisms.