If the value of x1x2x3y1y2y3111 is zero for three points (x1,y1),(x2,y2),(x3,y3), what can be concluded about these points?
(a) They form an equilateral triangle
(b) They are collinear
(c) They form a right-angled triangle
(d) The centroid of the triangle formed by them is at the origin