If a variable line passes through the point of intersectionof the lines `x + 2y - 1 = 0` and `2x - y-1 = 0` and meets the coordinate axes in `A` and `B`, then the locus of the midpoint of `AB` is : (A) ` x + 3y = 0` (B) `x + 3y = 10` (C) `x + 3y = 10xy` (D) None of these
A. x + 3y = 0
B. x + 3y = 10
C. x + 3y = 10xy
D. none of these