If ` vec a , vec b , vec c , vec d` are non-zero, non collinear vectors and if `( vec ax vec b)x( vec cx vec d)dot( vec ax vec d)=0` , then which of the following is always true. ` vec a , vec b , vec c , vec d` are necessarily coplanar either ` vec a` or ` vec d` must lie in the plane of ` vec b` and ` vec c` either ` vec b` or ` vec c` must lie in plane of ` vec a` and ` vec d` either ` vec a` or ` vec b` must lie in plane of ` vec c` and ` vec d`