Really? I don't believe it

Geometry Level 3

$A$ and $B$ are two points in $\mathbb{R}^2$ . What is the locus of points such that the ratio of the distances from $A$ and $B$ is always $\lambda:1$ , where $\lambda$ is a positive real number not equal to $1?$

Straight line Circle Hyperbola Catenary Nondegenerate parabola Non-circle ellipse Finite set of points None of the above