$X$ is $1$ km northeast of $Y.$ $Y$ is $1$ km southeast of $Z.$ $W$ is $1$ km west of $Z.$ $P$ is $1$ km south of $W.$ $Q$ is $1$ km east of $P.$ What is the distance between $X$ and $Q$ in km?

1. $1$
2. $\sqrt{2}$
3. $\sqrt{3}$
4. $2$