Which One of These Statements Is Incorrect

Multiple Choice

Which one of these statements is incorrect?

A) Real cash flows must be discounted at a real discount rate.
B) (1 + real rate of interest) = (1 + nominal rate of interest) / (1 + inflation rate)
C) The actual real rate of interest almost equals "nominal rate of interest − inflation rate."
D) Inflation rate = nominal rate / real rate − 1