Answer:
Option C
Explanation:
Let temperature of middle plate in steady state is $T_{0}$
$Q_{1}=Q_{2}$
Q= net rate of heat flow
$\therefore$ $\sigma A(3T)^{4}-\sigma AT_{0}^{4}=\sigma AT_{0}^{4}-\sigma A(2T)^{4}$
Solving this equation , we get
$T_{0}=\left(\frac{97}{2}\right)^{\frac{1}{4}}T$