Answer:
The second investor earned a higher return.
Explanation:
The first investor earns 1.5% for ten years. There is no discount of inflation because the interest rate is already protected.
In the other hand, and according to fisher, is necessary to discount the inflation to the nominal rate and that's going to be the real interest received by the second investor.
Real interest rate = Nominal - inflation
Real interest rate = 4.2% - 2% = 2.2% anual
Comparing both rates we find that