The correct answer is C - profile.
A soil profile is the vertical section of the soil from the ground surface downwards to where the soil meets the underlying rock. The soil profile can be as little as 10cm thick in immature soils and as deep as several meters in tropical areas where the climate is conducive to rapid alteration of the underlying rock to form soil.
In temperate areas, the soil profile is often found a meter deep and in arid areas it is generally shallower than this.