Mohammed and his wife have applied for a $350,000 mortgage to be amortized over 25 years at a fixed rate of 2.8% and a 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 $325. Their gross combined monthly income is $12,000. What is their Gross Debt Service (GDS) ratio?

1. 20.09%

2. 19.34%

3. 22.74%

4. 16.22%