Highlighted is correct

Please help me by explaining why.

Thank you.

7. To use the present value formula PVO = C/r-C/((1+r)**T*r)) at time zero, which of the following is correct? b. There are an infinite number of cash flows in the future There are at least one billion pieces of cash flows The number of cash flows cannot be counted The first piece of cash flows starts in the next period None of the above