Answer
A
Work Step by Step
Entropy balance:
$\dot{S}_{in}-\dot{S}_{out}+\dot{S}_{gen}=\Delta\dot{S}_{sys}$
$\dot{Q}/T_1-\dot{Q}/T_2+\dot{S}_{gen}=0$
Given $\dot{Q}=800\ W,\ T_1=293\ K,\ T_2=278\ K$
$\dot{S}_{gen}=0.147\ W/K$
Since $\dot{X}_{dest}=T_0\dot{S}_{gen}$
$\dot{X}_{dest}=40.3\ W$
