The correct answer is: D. Saran, Siwan
The Kamla Canal is a canal in the Indian state of Bihar. It is a branch canal of the Sone Canal, and it irrigates the districts of Saran and Siwan. The canal was built in the early 19th century, and it is one of the most important irrigation canals in Bihar.
The canal is about 100 kilometers long, and it has a command area of about 200,000 hectares. The canal irrigates a variety of crops, including rice, wheat, sugarcane, and maize. The canal also provides drinking water to a number of villages in the region.
The Kamla Canal is an important source of irrigation and drinking water for the people of Saran and Siwan districts. The canal has helped to improve the agricultural productivity of the region, and it has also helped to improve the quality of life for the people living in the region.
The other options are incorrect because they do not irrigate the districts of Saran and Siwan. Option A is incorrect because it irrigates the districts of East and West Champaran. Option B is incorrect because it irrigates the districts of Muzaffarpur and Sitamarhi. Option C is incorrect because it irrigates the districts of Darbhanga and Madhubani.