For a Cube-Shaped Room, 10 Ft on a Side, What $\degree$

Multiple Choice

For a cube-shaped room, 10 ft on a side, what will be the rate of heat loss if the R-value is 4 ft2- $\degree$ F-hr/Btu for each side and the $\Delta$ T is 50 F?

A) 800
B) 1200
C) 5000
D) 7500
E) 12,000 Btu/hr