Soil horizons are defined by physical features. Please select the best answer from the choices provided
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A soil horizon is a layer parallel to the soil surface, whose physical characteristics differ from the layers above and beneath. ... Horizons are defined in most cases by obvious physical features, chiefly colour and texture.

Explanation:

the answer is c.) there is a warm front in region a and a stationary front in region b.

the endomembrane system i think