The condition for the coaxial system $x^2+y^2+2 \lambda x +c=0,$ where $\lambda$ is a parameter and c is a constant to have distinct limiting points, is

Question

\[\begin {array} {1 1} (a)\;c=0 & \quad (b)\;c < 0 \\ (c)\;c=-1 & \quad (d)\; c > 0 \end {array}\]