Which one is right, according to population in soil?

Answer: Option A

The soil population consists of organisms constantly found in the soil (autochinous flora) and organisms present in the soil only in the form of spores (bacteria and fungi).
According to the population in the soil, Bacteria are more in number than actinomycetes, which is more than fungi. The microbial population of the soil is determined by soil depth, organic matter, porosity, oxygen and carbon dioxide concentration and soil pH.