c
$P=\sigma A T^{4}$
Intensity $\frac{P}{\mathrm{A}}=\sigma \mathrm{T}^{4}$
$\Rightarrow 5.67 \times 10^{4}=5.67 \times 10^{-8} \times \mathrm{T}^{4}$
$\Rightarrow \mathrm{T}^{4}=10^{12}$
$\Rightarrow \mathrm{T}=1000 \mathrm{K}$
$\mathrm{T}=727^{\circ} \mathrm{C}$