If x% is the gradient of an alignment and y% is the gradient after proper super-elevation along a
curved portion of a highway, the differential grade along the curve, is
(A) (x + y) %
(B) (x - y) %
(C) (y - x) %
(D) (y + x) %
curved portion of a highway, the differential grade along the curve, is
(A) (x + y) %
(B) (x - y) %
(C) (y - x) %
(D) (y + x) %