$\begin{array}{1 1}(A)\;x-y+1=0 \; ; \; 3x+y+7=0 \\(B)\;x+y+1=0 \; ; \; 3x-y-7=0 \\(C)\;x+y-1=0 \; ; \; 3x-y+7=0 \\(D)\;none\;of \;these \end{array}$