Let {x,y,z,w} 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}