Cigna, Inc., a large conglomerate firm, plans to build a new tollway. The cost (NINV) of the project is expected to be $3.2 billion. Net cash inflows are expected to equal $978 million per year. How many years must the firm generate this cash inflow stream for investors to earn their required 28 percent rate of return? Around 8 years Around 10 years Around 6 years Around 3 years