A Brass Rod with a Length of 10 $^{\circ}$ C and a Cold Temperature of 10

A brass rod with a length of 10.0 cm is placed end to end with an aluminum rod with a length of 30.0 cm and this system is placed between a hot temperature of 100 $^{\circ}$ C and a cold temperature of 10.0 $^{\circ}$ C.The coefficient of thermal conductivities of the brass and the aluminum are 100 W/m C and 230 W/m $^{\circ}$ C respectively.The rods have the same cross sectional area of 20.0 cm².What is the heat flow from the hot temperature to the cold temperature?

A) 55.3 W
B) 65.3 W
C) 70.3 W
D) 78.1 W
E) 85.3 W