You can only answer c)

In this exercise, we want to derive and construct different examples: a) Give an example of a pair (primal and dual) of linear optimization problems such that both the primal and the dual problem have unique optimal solutions. b) Give an example of a pair (primal and dual) of linear programs such that the primal problem has multiple solutions, but the dual problem has a unique optimal solution. c) Give an example in which there is a duality gap between the primal and dual problem, i.e., the optimal objective function values of the primal and dual problem do not coincide