Chemical Thermodynamics: JEE Main 2023 Chemistry question

Given .tg {border-collapse:collapse;border-spacing:0;} .tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; overflow:hidden;padding:10px 5px;word-break:normal;} .tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;} .tg .tg-baqh{text-align:center;vertical-align:top} .tg .tg-0lax{text-align:left;vertical-align:top} (A) $\mathrm{2CO(g)+O_2(g)\to 2CO_2(g)}$ $\mathrm{\Delta H_1^0=-x~kJ~mol^{-1}}$ (B) $\mathrm{C(graphite)+O_2(g)\to CO_2(g)}$ $\mathrm{\Delta H_2^0=-y~kJ~mol^{-1}}$ $\mathrm{\Delta H^0}$ for the reaction $\mathrm{C(graphite)+\frac{1}{2}O_2(g)\to CO(g)}$ is :