Which of the following statements is true?

a. The riskier a future cash flow, the less valuable it is today (in present value terms).

b. If the size of a future cash flow from an asset is uncertain, it cannot be considered in estimating the value of the asset.

c. Both of the above.

d. None of the above..

I am wondering which of these is the correct answer and why, please. Moreover, I chose D for this question and it is wrong.