Which of the following statement is true?

a. We can find the nominal interest rate by subtracting the real rate and inflation rate and inflation from the sum of the default and maturity premiums.

b. If prices rise by 3% and your salary increase by 5% you would experience a gain of purchasing, power.

c. You would never earn a positive rate of return by purchasing zero coupon bonds at discount and holding them to maturity.

d. Borrowers want to protect their purchasing power reward from being wiped out by lower inflation.