Calculate the monthly payment for the period of time after the 1st interest rate adjustment with principal amount at that time - $450,000, initial amortization term 20 years, initial interest rate 3.5%, interest rate after 1st adjustment - 4.5% at 5th year of loan. a. $2,846 b. $2,280 c. $3,442 d. none of the above. Select one: O a. a b. b C. C O d. d