In this question , we have to remeber the rule of combining two negative numbers . And the rule is, when combining two negative terms, we have to add them with negative sign .For e.g.-2-15=-(2+15)=17. SImilarly, -3 -14 =-(3+14)=-17. And none of them got -17. Dominique got 11 and Juan got 17. So none of them is correct .