The lines (x - 1)/l = (y + 2)/m = (z - 4)/n and (x + 3)/2 = (y - 4)/3 = z/6 are parallel to each other if :
(a) 2l = 3m = n
(b) 3l = 2m = n
(c) 2l + 3m + 6n = 0
(d) lmn = 36
Answer is (b) 3l = 2m = n
