The equation representing the set of points which are equidistant from the points (1, 2 , 3) and ( 3 , 2 , -1) is
2x - 2y = 0
x - 2z = 0
-x + 2y = 0
x - 2y = 0
The equation of the set of points which are equidistant from (1,2,3) and (3,2,-1).