If 0 is the angle between two lines whose d.c.s are 1. m. n and 12. m2. n2, then the d.cs of one of the angular bisectors of the two lines are A B C D 11+12 m+m n1 + 12 2 2 2 11 + 12 mm n1 + n 0 0 2 cos() 2 cos() 2 cos(-) 1+12 mm2 n + 0 +2 cos() cos() cos( DIN 11+12 mm nj+n2 0 2 sin() 2 sin() 2 sin()