What is the correct explanation for the concentric pattern shown in the south-eastern area of this region?
(A) This structure was formed by mining activities, so it has an anthropogenic origin.
(B) The feature was gradually formed from sediments deposited by the rivers flowing from the East.
(C) The area was raised by tectonic forces; the middle of the concentric contours coincides with the maximum rising.
(D) A wall of trees in the Southeast held back the water flowing from the Northeast, causing sediments to accumulate.