Answer:
D. higher than the equilibrium interest rate.
Explanation:
The Fisher equation at equilibrium ; i = r + τe helps you to answer this question whereby;
i = nominal interest rate
r = real interest rate
τe = expected inflation rate
If we re-write it beginning with real interest rate ; r = i - τe .
So, considering the above equation, if the actual inflation rate turns out to be lower than expected , we will have a lower τe and the difference (i - τe) will be bigger making the real interest rate higher than equilibrium.