Let `vec a, vec b, vec c` be unit vectors such that `vec a + vec b + vec c = vec 0`. Which one of the following is correct?

Options

A. `vec a xx vec b = vec b xx vec c = vec c xx vec a = vec O`
B. `vec a xx vec b = vec b xx vec c = vec c xx vec a ne vec O`
C. `vec a xx vec b = vec b xx vec c = vec a xx vec c = vec O`
D. `vec a xx vec b , vec b xx vec c, vec c xx vec a` are mutually perpendicular

Answer

B