Explanation: In the context of Bihar's agricultural practices, certain crops are grown both as Kharif (summer) and Rabi (winter) crops. These crops are essential for food and fodder production in the region. The ideal conditions for these crops include specific temperature ranges and soil types that support their growth and yield.
The temperature range for these crops is crucial. The correct temperature range for optimal growth is 21$^{\circ}$-27$^{\circ}$ C. This range is suitable for both Kharif and Rabi crops because it provides a moderate climate that supports the growth of a variety of crops. Temperatures outside this range, such as those in options A and D (25$^{\circ}$-35$^{\circ}$ C), are too high and can lead to stress on the plants, reducing their yield and quality.
The soil type is also a critical factor. In Bihar, the soil is predominantly alluvial, which is formed by the deposition of silt and clay by rivers. Old alluvial soil, as mentioned in the correct option C, is more suitable for food and fodder crops. This soil type is rich in nutrients and has a good water retention capacity, which is essential for crop growth. New alluvial soil, as mentioned in option B, is less nutrient-rich and may not provide the same level of support for these crops.
It is important to note that the combination of the correct temperature range and soil type is crucial for the successful cultivation of food and fodder crops in Bihar. The ideal conditions ensure that the crops receive the necessary environmental factors to grow and produce a high yield. Understanding these conditions is essential for farmers and agriculturalists in Bihar to maximize their crop production and ensure food security in the region.
In summary, the correct answer is option C, which specifies the ideal temperature range of 21$^{\circ}$-27$^{\circ}$ C and the suitable soil type of old alluvial for the cultivation of food and fodder crops in Bihar. This combination provides the optimal conditions for crop growth and yield, supporting the agricultural practices in the region.