For a reaction to be spontaneous, the change in Gibbs free energy ($\Delta G$) must be negative ($\Delta G < 0$). According to the Gibbs equation, $\Delta G = \Delta H - T\Delta S$. For $\Delta G < 0$, $\Delta H - T\Delta S < 0$, which implies $T > \frac{\Delta H}{\Delta S}$. Given: $\Delta H = 170 \text{ kJ} = 170000 \text{ J}$ $\Delta S = 170 \text{ J K}^{-1}$ Substituting the values: $T > \frac{170000 \text{ J}}{170 \text{ J K}^{-1}}$ $T > 1000 \text{ K}$ Among the given options, only $1110 \text{ K}$ is greater than $1000 \text{ K}$. Therefore, the reaction will be spontaneous at $1110 \text{ K}$ .