Let {X, Y, Z, IV) be an independent set in Rn. Which of the following sets is independent? Support your answer.
(a) {X - Y, Y-Z,Z-X]
(b) {X + Y, Y+Z,Z + X)
(c) {X - Y, Y-Z, Z- W, W - X)
(d) {X + Y, Y+Z, Z+ W, W +X}