The correct option is B acidic, alkaline
Rainfall and irrigation control the pH of most soils. In humid climates, heavy rainfall percolates through the soil. When it does, it leaches basic ions such as calcium and magnesium and replaces them with acidic ions such as hydrogen and aluminium.
In arid regions soils tend to be alkaline. Rainfall is not heavy enough to leach basic ions from soils in these areas. As a result, areas with heavier rainfall will have more acidic soil, while areas with dry climates will have more alkaline soil.