Answer:
The answer is c. present value index
Step-by-step explanation:
Present value index is the ratio decided by dividing net present value of the project by its require initial net cash outflows.
Once having constraint on selecting investment with positive NPV to be made due to lack of fund, a firm's usually use Present value index for further decision making.
The investment with higher present value index shows that it generates more net cash flow or in other words, more efficient and requires less initial cash outflow, and thus usually be chosen over the other ones with lower present value index.