At temperature above $1073\mathrm{K},$ coke can be used to reduce ${\mathrm{Fe}}_2{\mathrm{O}}_3$ to $\mathrm{Fe}$. How can you justify this reduction with the Ellingham diagram?

Free energy of formation ${∆}_{\mathrm{f}}\mathrm{G}$ of $\mathrm{MgO} \left(\mathrm{s}\right) \mathrm{and} \mathrm{CO} \left(\mathrm{g}\right)$ at $1273\mathrm{K}$ and $2273\mathrm{K}$ are given below:
${\mathrm{\Delta }}_{\mathrm{f}}\mathrm{G} \mathrm{MgO} \left(\mathrm{s}\right)=-941 \mathrm{kJ} {\mathrm{mol}}^{-1}$                at $1273\mathrm{K}$
${\mathrm{\Delta }}_{\mathrm{f}}\mathrm{G} \mathrm{MgO} \left(\mathrm{s}\right)=-314 \mathrm{kJ} {\mathrm{mol}}^{-1}$                at $2273\mathrm{K}$
${\mathrm{\Delta }}_{\mathrm{f}}\mathrm{G} \mathrm{CO} \left(\mathrm{g}\right)=-439 \mathrm{kJ} {\mathrm{mol}}^{-1}$                   at $1273\mathrm{K}$
${\mathrm{\Delta }}_{\mathrm{f}}\mathrm{G} \mathrm{CO} \left(\mathrm{g}\right)=-628 \mathrm{kJ} {\mathrm{mol}}^{-1}$                   at $2273\mathrm{K}$
At what temperature can $\mathrm{MgO}$ be reduced by carbon?

In Ellingham diagram, the slope of the curve of the formation of metal oxide:

Which of the following statements is true? 

Which of the following is correct regarding the given diagram of reduction of haematite? 

Consider the following reactions at $1000° \mathrm{C}$

$\left(\mathrm{A}\right)$ $Zn\left(\mathrm{s}\right)+\frac{1}{2}{\mathrm{O}}_2 \left(\mathrm{g}\right)⟶\mathrm{ZnO} \left(\mathrm{s}\right); \mathrm{\Delta G}°=-360 \mathrm{kJ} {\mathrm{mol}}^{-1}$
$\left(\mathrm{B}\right)$ $\mathrm{C} \left(\mathrm{s}\right)+\frac{1}{2}{\mathrm{O}}_2 \left(\mathrm{g}\right)⟶\mathrm{CO} \left(\mathrm{g}\right); \mathrm{\Delta G}°=-460 \mathrm{kJ} {\mathrm{mol}}^{-1}$

Choose the correct statement at $1000° \mathrm{C}$.