Correct option is (b) Thiesson method
For explanation: Thiesson method is very accurate compared to other methods and is generally used when the catchment area lies between 500 to 5000km square. Assume that there are stations in the given basin names=d as 1, 2, 3, 4, 5, 6, 7, and 8. It is very important to divide the total basin area in such a way that each located station in the basin represents that area in the true.