Answer: 6.06%
Explanation:
We must use the equation (1 + r/n)^n - 1.
r = percent rate
n = number of times compounded per year
While it is an annual percentage yield, it is still being compounded monthly.
So n = 12, not 1.
We also know 5.9% as a decimal should be 0.059.
The final equation should be (1 + 0.059/12)^12 - 1 = 0.0606
0.0606 x 100 = 6.06%
Hope this helped! :)