Comprehensive and Detailed In-Depth Explanation:

The discounted payback period is a capital budgeting technique that determines how long it takes for a project to recover its initial investment, accounting for the time value of money.

Option A (Calculates the overall project value) describes Net Present Value (NPV), not the payback period.

Option B (Ignores the time value of money) applies to the simple payback period, but the discounted payback period does account for the time value of money.

Option D (Begins at time zero) is true for all capital budgeting methods, not specific to this one.

Thus, option C is correct because the discounted payback period measures the break-even time while considering the present value of cash flows.