Let u=-15i+3j-3k, v=5i-j+k, w=j - 5k. Which vectors, if any are (a) perpendicular? (b) Parallel? (a) Which vectors are perpendicular? Select the correct choice below and fill in the answer box(es) within your choice. OA. The vectors are perpendicular. (Use a comma to separate answers as needed.) OB. Vector is perpendicular to vectors OC. None of the vectors are perpendicular. (Use a comma to separate answers as needed.)