A wall is made of brick, with a thermal conductivity of 1.0 W/m-K, 230 mm thick, lined on the inner face with plaster of thermal conductivity 0.4 W/m-K and a thickness of 10 mm. If a temperature difference of 30 K is maintained between the two outer faces, what is the heat flow per unit area of the wall?
A. 110 W
B. 119 W
C. 129 W
D. 140 W