The correct answer is: C. Saran
Saran district has the highest population density in Bihar, with 1,281 persons per square kilometer. This is followed by Siwan district with 1,257 persons per square kilometer, Sheohar district with 1,236 persons per square kilometer, and Sitamarhi district with 1,194 persons per square kilometer.
The population density of a district is calculated by dividing the total population of the district by the area of the district. Saran district has a total population of 4,085,347 and an area of 3,174 square kilometers. Siwan district has a total population of 3,848,592 and an area of 3,114 square kilometers. Sheohar district has a total population of 1,929,906 and an area of 1,554 square kilometers. Sitamarhi district has a total population of 2,354,983 and an area of 2,028 square kilometers.
The high population density in Saran district is due to a number of factors, including its location in the Gangetic plain, its fertile soil, and its proximity to the state capital, Patna. The Gangetic plain is a fertile region that is well-suited for agriculture. This has led to a high population density in the region, as people have moved to the area to farm the land. Saran district is also located close to the state capital, Patna. This has made it a popular destination for people who are looking for work or education. The high population density in Saran district has a number of implications, including the need for more infrastructure, such as roads, schools, and hospitals. It also puts a strain on the environment, as more people use natural resources such as water and land.