Find the Distance Between the Pair of Points $(m, m+n)$ And $(m-n, n)$

Multiple Choice

Find the distance between the pair of points.
- $(m, m+n)$ and $(m-n, n)$

A) $n-m$
B) $\sqrt{n^{2}+m^{2}}$
C) $\sqrt{n^{2}-m^{2}}$
D) $n+m$