Final answer:
If the unemployment rate changes to 18.6% and overall price levels remain constant, the current year nominal GDP can be calculated using the formula (Real GDP / (1 - Unemployment Rate)).
Step-by-step explanation:
If the unemployment rate changes to 18.6% and overall price levels remain constant, the previous year nominal GDP of $28.9 trillion can be used to calculate the current year nominal GDP. We can use the formula: (Real GDP / (1 - Unemployment Rate)). So, using the given information, the current year nominal GDP would be approximately $31.3 trillion. Therefore, none of the choices provided are correct.