If the Nominal Interest Rate Is 10 Per Cent, the Inflation

If the nominal interest rate is 10 per cent, the inflation rate is 6 per cent, and the tax rate on interest income is 25 per cent, what is the after-tax real interest rate?

A) 3.5 per cent
B) 1.5 per cent
C) 6.0 per cent
D) 4.0 per cent
E) 3.0 per cent