Mohammed and his wife have applied for a $300,000 mortgage to be amortized over 25 years at a fixed rate of 3.5% and a fixed term of 5 years. Payments will be monthly. The Bank of Canada benchmark 5-year fixed insured mortgage rate is 5.25%. The couple expect monthly heating and property taxes will amount to $600. Their gross combined monthly income is $12,000. What is their Gross Debt Service (GDS) ratio? A 17.48% B 19.90% C 20.26% (D) 18.67%