The correct answer is D. All of the above.
An analysis and estimation of cash flows includes input data, key output, depreciation schedule, and net salvage values.
Input data is the information that is used to estimate cash flows. This information can include historical data, market data, and expert opinions.
Key output is the information that is most important to decision-makers. This information can include the net present value, internal rate of return, and payback period.
Depreciation schedule is a schedule that shows how the value of an asset is reduced over time. This schedule is used to calculate depreciation expense, which is a non-cash expense.
Net salvage value is the estimated value of an asset at the end of its useful life. This value is used to calculate the terminal cash flow.
All of these items are important for an analysis and estimation of cash flows.