Supose directioncoisnes of two lines are given by `u l+vm+wn=0 and al^2+bm^2+cn^2=0` where u,v,w,a,b,c are arbitrary constnts and l,m,n are directioncosines of the lines. For `u=v=w=1` if `(n_1 n_2)/(l_1 l_2)=((a+b)/(b+c))` then (A) `(m_1m_2)/(l_1 l_2)=((b+c))/((c+a))` (B) `(m_1m_2)/(l_1 l_2)=((c+a))/((b+c))` (C) `(m_1m_2)/(l_1 l_2)=((a+b))/((c+a))` (D) `(m_1m_2)/(l_1 l_2)=((c+a))/((a+b))`