Which of the Following Is $\textbf{ not }$

Which of the following is $\textbf{ not }$ an assumption of the internal rate of return model?

A) The amount and timing of all cash flows is known exactly
B) All cash flows occur at the end of the year
C) Cash inflows from the project are reinvested in another project earning a return equal to the internal rate of return
D) All of these ans choices are assumptions of the internal rate of return model.