Given the following network diagram with three sites $($A$,$ B$,$ and C$)$ and these IP network addresses:

Wide area network connecting the $3$ sites with an IP network: $10\mathrm{.}10\mathrm{.}1\mathrm{.}0($mask: $255\mathrm{.}255\mathrm{.}255\mathrm{.}0)$

LAN A: $192\mathrm{.}168\mathrm{.}16\mathrm{.}0$

LAN B: $192\mathrm{.}168\mathrm{.}17\mathrm{.}0$

LAN C: $192\mathrm{.}168\mathrm{.}18\mathrm{.}0$