Ans: A
Note that there are two fixed points $A$ and $B$, and the moving point $P$ is equidistant to the two fixed point. Therefore, the locus of $P$ is the perpendicular bisector of $AB$.
Note that there are two fixed points $A$ and $B$, and the moving point $P$ is equidistant to the two fixed point. Therefore, the locus of $P$ is the perpendicular bisector of $AB$.
