The correct answer is D. All of the above.
Siwan, Saran, and Gopalganj are all districts in Bihar that use well irrigation technique. Well irrigation is a method of irrigation that uses wells to extract groundwater and distribute it to crops. It is a common method of irrigation in many parts of the world, including Bihar.
Well irrigation has several advantages over other methods of irrigation, such as surface irrigation. It is more efficient in terms of water use, as it allows farmers to target the water directly to the crops. It is also more reliable, as it is not affected by rainfall or other weather conditions.
However, well irrigation also has some disadvantages. It can be expensive to install and maintain wells. It can also be a source of pollution, as the water from wells can contain harmful chemicals or bacteria.
Overall, well irrigation is a valuable tool for farmers in Bihar. It is an efficient and reliable method of irrigation that can help to increase crop yields. However, it is important to be aware of the potential disadvantages of well irrigation before using it.
Here is a brief explanation of each option:
- Option A: Siwan is a district in Bihar that uses well irrigation technique. Well irrigation is a method of irrigation that uses wells to extract groundwater and distribute it to crops. It is a common method of irrigation in many parts of the world, including Bihar.
- Option B: Saran is a district in Bihar that uses well irrigation technique. Well irrigation is a method of irrigation that uses wells to extract groundwater and distribute it to crops. It is a common method of irrigation in many parts of the world, including Bihar.
- Option C: Gopalganj is a district in Bihar that uses well irrigation technique. Well irrigation is a method of irrigation that uses wells to extract groundwater and distribute it to crops. It is a common method of irrigation in many parts of the world, including Bihar.