Calculate the standard enthalpy of reaction for the following reaction using the listed enthalpies of reaction :
$$
\begin{aligned}
3 \mathrm{Co}(s)+2 \mathrm{O}_{2}(g) & \longrightarrow \mathrm{Co}_{3} \mathrm{O}_{4}(s) \\
2 \mathrm{Co}(s)+\mathrm{O}_{2}(g) & \longrightarrow 2 \mathrm{CoO}(s) ; \quad \Delta H_{1}^{\circ}=-475.8 \mathrm{~kJ} \\
6 \mathrm{CoO}(s)+\mathrm{O}_{2}(g) & \longrightarrow 2 \mathrm{Co}_{3} \mathrm{O}_{4}(s) ; \Delta H_{2}^{\circ}=-355.0 \mathrm{~kJ}
\end{aligned}
$$
(a) $-891.2 \mathrm{~kJ}$
(b) $-120.8 \mathrm{~kJ}$
(c) $+891.2 \mathrm{~kJ}$
(d) $-830.8 \mathrm{~kJ}$