How should we write the boundary condition on side 2 of this slab? \text { A. }-\left.k \frac{d T}{d x}\right|_{x=0}=h\left(T_{\infty}-T_{2}\right) \text { B. } \quad-\left.k \frac{d T}{d x}\right|_{x=L}=h\left(T_{\infty}-T_{2}\right) \text {

C. }-\left.k \frac{d T}{d x}\right|_{x=L}=h\left(T_{2}-T_{\infty}\right)