→OA=3i+4j+12k,→OB=12i+3j+4k, →OC=4i+12j+3k.
Find the unit vector perpendicular to →OA and →OB
a. 20i−132j+39k/√(19345)
b. −20i+132j−39k/√(19345)
c. −50i+156j−57k/√(30085)
d. 50−156j+57k/√(30085)