In a $CAD$ package, mirror image of a $2D$ point $P(5,10)$ is to be obtained about a line which passes through the origin and makes an angle of $45^{\circ}$ counterclockwise with the $X$-axis. The coordinates of the transformed point will be

- $(7.5, 5)$
- $(10, 5)$
- $(7.5, -5)$
- $(10, -5)$