The correct option is B 1√3(^i+^j+^k)
We know that the unit vector perpendicular to two vectors is given as
^n=→A×→B|→A×→B|
So, we have →A×→B as per determinant method as
⎡⎢⎣^i^j^k1−213−2−1⎤⎥⎦
⇒ (2−(−2))^i−(−1−3)^j+(−2−(−6))^k
⇒ 4^i+4^j+4^k
Also, |→A×→B|=√42+42+42=4√3
Hence, ^n=→A×→B|→A×→B|=4^i+4^j+4^k4√3=1√3(^i+^j+^k)