[" 7.7.Vector of length "3" unit which is perpendicular to "hat i+hat j+hat k" and lies in the plane of "hat i+hat j+hat k" and "2hat i-3hat j," is "],[[" (A) "(3)/(sqrt(6))(hat i-2hat j+hat k)," (B) "(3)/(sqrt(6))(2hat i-hat j-hat k)," (C) "(3)/(sqrt(114))(7hat i+8hat j+hat k)" (D) "(3)/(sqrt(114))(-7hat i+8hat j-hat k)]]