ABC is a right-angled triangle, right angled at B. The triangle rotates about B such that C and A always lie on two perpendicular lines OX, OY, respectively. The locus of centroid of ΔABC is
(A) A straight line parallel to the perpendicular bisector of OB
(B) A straight line perpendicular to OA
(C) A circle centered at midpoint of OB
(D) None of these