A small firm wants to use port address translation $($PAT$)$ to enable the office computers to access the Internet. The computers use internal private addresses in the range of $192\mathrm{.}68\mathrm{.}1\mathrm{.}100$ through $192\mathrm{.}68\mathrm{.}1\mathrm{.}200.$ The shared public IP address is $172\mathrm{.}124\mathrm{.}10\mathrm{.}10.$ Which of the following is a legitimate shared PAT address?