With increase in soil depth, CO2 content . . . . . . . .

Answer: Option B

With the increase in soil depth, CO₂ content Increases. Carbon dioxide content in soil is about 0.25% while carbon content in the atmosphere is only 0.04%. The soil can store more carbon when it is protected from microbial activity. Gases fill soil pores in the soil structure as water drains or is removed from a soil pore by evaporation or root absorption.