What is the correct explanation forthe concentric pattern shown in thesouth-eastern area of this region?
(A) This structure was formed bymining activities, so it has ananthropogenic origin.
(B) The feature was gradually formedfrom sediments deposited by therivers flowing from the East.
(C) The area was raised by tectonicforces; the middle of theconcentric contours coincideswith the maximum rising.
(D) A wall of trees in the Southeastheld back the water flowing fromthe Northeast, causing sedimentsto accumulate.