The correct answer is: A. no inflation.
The real rate of interest is the rate of interest that is adjusted for inflation. It is calculated by subtracting the inflation rate from the nominal interest rate. The nominal interest rate is the interest rate that is actually paid on a loan.
If there is no inflation, then the real rate of interest will be equal to the nominal interest rate. This is because the nominal interest rate will already take into account the expected rate of inflation.
If there is high inflation, then the real rate of interest will be less than the nominal interest rate. This is because the nominal interest rate will not be able to keep up with the rate of inflation.
If there are no transactions, then the real rate of interest will be zero. This is because there will be no change in the value of money.
If there is no acceleration, then the real rate of interest will be the same as the nominal interest rate. This is because there will be no change in the rate of inflation.