Which of the following factors should be considered when valuing a real estate investment? 1. After-tax cash flow, calculated as net after-tax earnings, plus depreciation minus principal repayment 2. Net operating income divided by an appropriate capitalization rate. 3. The cost of the investment, which is calculated by adding maintenance costs, depreciation, and taxes to the purchase price, in comparison to other investment options. a) 1 only Ob) 1 and 2 Oc) 2 and 3 d) 1, 2, and 3