C. The local government is to decide whether to extend the Train "Red" line from Medway to Augusta. The values of the extension for people living in Medway and Augusta are a and b respectively. The cost of construction is c > 0. The government wants to go ahead with the construction if and only if a + b >= c. The values a and b are known by the residents of Medway and Augusta but not by the Government; c is known to everybody. To learn these values, the Government asks each neighborhood (Medway and Augusta) to submit the value of the construction to the locality. Given the submitted valuations va and vb, which need to be non-negative, the government constructs the bridge if and only if va + vb >= c, and taxes Medway and Augusta ta(va, vb) and tb(va, vb) respectively, where:
c - vb if va + vb and vb < c,
0 otherwise.
c - va if va + vc and va < c,
0 otherwise.
Does there exist a dominant strategy equilibrium (DSE) in this game? If so, find one.