A business is evaluating two mutually exclusive projects. Project A requires an immediate investment of $$3000,$ plus another $$4000$ in three years. It would produce a profit of $$3000$ in the second year, $$9,000$ in the fourth year, and $$6,000$ in the seventh year. Project $B$ requires an immediate investment of $$6000,$ another $$7000$ in two years, and a further $$5000$ in four years. It would produce an annual profit of $$5400$ for seven years. Neither project would have any residual value after seven years. Which project should be selected if the required rate of return is $7\%?$ What is the economic advantage, in current dollars, of the preferred project?