The two main elements of climate which affect soil formation are

The two main elements of climate that affect soil formation are rainfall and temperature. Rainfall and temperature are important factors in the formation of soil because they influence the rate at which chemical and physical weathering occurs. Chemical weathering involves the breakdown of rocks and minerals through chemical processes, while physical weathering involves the breakdown of rocks and minerals through physical processes such as freeze-thaw cycles. Rainfall is important in soil formation because it helps to break down rocks and minerals through chemical weathering. It also provides the water necessary for plant growth, which contributes to the formation of organic matter in the soil. Temperature is also important in soil formation because it influences the rate at which chemical and physical weathering occurs. Higher temperatures generally lead to faster rates of weathering, while lower temperatures lead to slower rates of weathering. Therefore, the correct option is A, "rainfall and temperature", as these two elements have the most significant impact on the formation of soil. The other options, air, light, wind, and relative humidity, are also important factors in soil formation, but they are not as significant as rainfall and temperature.