Let A(x1 , y1), B(x2 , y2) C(x3 , y3) be vertices of triangle ABC with BC = a, AB = c, AC = b. If algebraic sum of perpendicular distances from L (3ax1/ a + b + c , 3cy3/ a + b + c) , M (3bx2/ a + b + c , 3by2/ a + b + c), N (3cx3/ a + b + c , 3cy3/ a + b + c) to a variable line is zero then all such lines passes through
(A) orthocentre of ΔABC
(B) centroid of ΔABC
(C) circumcentre of ΔABC
(D) in centre of ΔABC