A 10-Cm Copper Cube Sits on a Heat Source with a 10-Cm

A 10-cm copper cube sits on a heat source with a 10-cm cube of ice sitting on top of the copper cube.What is the minimum required temperature of the heat source if all of the ice is to melt in 154 seconds? The density of ice is 917 kg/m³ and the thermal conductivity of copper is 386 W/(m·K) .

A) 79 ^$\circ$ C
B) 109 ^$\circ$ C
C) 100 ^$\circ$ C
D) 54 ^$\circ$ C
E) 65 ^$\circ$ C