2)a soil's texture is determined by
a)mineral composition
b)type of humus
c)water content
d)particle size

The correct answer is D)particle size

Explanation:

Different types of mineral particles present in soil determines the texture of a soil. The texture of soil is based on the sand, silt and clay particles present in the soil.  

Sand particles are the largest particles in the soil measuring between 0.05–2.0 mm, clay are smallest ranging less than 0.002 mm and slits are medium-sized particles ranging between 0.002–0.05 mm.

So the percentage of these three soil particles mainly decides the texture of the soil. For example, loamy soil has 20% clay, 40% silt, and 40% sand. Therefore the correct answer to this question is D)particle size.