1 question with multiple parts. Need assistance.

A. if you qualified for home mortgage of $425,000. What will your monthly payment be if the annual interest rate is 5.5%, It's fixed for 30 years and compounded monthly. B. it took you three months to find a home and the rate change, if the rate increased by 0.5 and the new rate is 6% your monthly payment cannot change from scenario A how much is the max new loan you can obtain for 30 years fixed compounded monthly? C. it took you three months to find a home and the rate change, if the rate decreased by 0.5 and the new rate is 5% your monthly payment cannot change from scenario A how much is the max new loan you can obtain for 30 years fixed compounded monthly? D. what is the tradeoff between 0.5 % in the rate and loan amount? (Your answer would be each 0.5% in rate is equivalent to $.............. in loan amount)