please use solver in excel

Seervada Park has recently been set aside for a limited amount of sightseeing and backpack hiking. Cars are not allowed into the park, but there is a narrow, winding road system for trams and for jeeps driven by the park rangers. The road system is shown below (without the curves), where location O is the entrance to the park; other letters designate the location of ranger stations (and other limited facilities). The numbers give the distance of these winding roads in miles. The park contains a scenic wonder point at station T. A small number of trams are used to transport sightseers from the park entrance to station T and back. A 2 2 7 5 T 5 4 0 B D 7 3 4 C E 4 A second problem park management needs to solve is that, because of the hilly terrain making cell communication spotty, telephone lines must be installed under all the roads to establish telephone communications among all the stations (including the park entrance). Because the installation is expensive and disruptive to the natural environment, lines will be installed under just enough roads such that all stations are connected to the telephone system. The question is, where the lines should be laid to accomplish this with a minimum number of miles of line installed. Solve this problem for the park management