A five-year loan is being repaid with level monthly installments, one at the end of each month beginning on 1/1/2018 and ending on 12/31/2022. A 12% nominal annual interest rate compounded monthly was used to determine the amount of each monthly installment.

In which of the following periods does the outstanding loan balance first fall below one-half of the original amount of the loan?

a) January 2018 through March 2020

b) April 2020 through June 2020

c) July 2020 through September 2020

d) October 2020 through December 2020

e) January 2021 through December 2022