4. Herring Beach Resort is appraising a January 1st 2020 investment of $11 million that will increase cash inflows by: $900,000 in 2020, $6,000,000 in 2021, $3,500,000 in 2022, $800,000 in 2023; and, $600,000 in 2024. At the end of 2024, it is estimated the investment can be salvaged for $6 million. What is the payback period for the investment? a. 3 years b. 3 years and 6 months c. 3 years and 9 months d. 4 years e. None of the above