Here all options are incorrect hence marks to ALL
V1=2I−J+k
V2=I+J-K
Their dot product is V1.V2=|V1||V2|cos ( theta) =0 if they are perpendiclar to each other
now (2i-j+k).(i+j-k)=2-1-1=0 hence theta =90 degree so choice B is out
To find vector perpendicular to V1and V2 we need a cross product of these two as below
i j k
2 -1 1 solving this determinant we get 0i+3j+3k which does not match any choice
1 1 -1
Aleternatively u can perform dot product of vectors given by choice A,C,D to V1 ,V2 result
of no choice will give u 0 hence they are not having 90degree angle with V1 and V2I+J−KI+J−KI+J−KI+J−KI+J−K