$\begin {array} {1 1} (A)\;x^2+y^2+4x-21=0 \: and \: x^2+y^2-12x+11=0 \\ (B)\;x^2+y^2-4x+21=0 \: and \: x^2+y^2+12x-11=0 \\ (C)\;x^2+y^2-4x-21=0 \: and \: x^2+y^2-12x-11=0 \\ (D)\;x^2+y^2+4x+21=0 \: and \: x^2+y^2+12x+11=0 \end {array}$