Two identical copper rods have the same length L but different cross-sectional areas. Rod 1 has area A and Rod 2 has area 2A. A temperature difference ΔT is maintained across each rod. Which of the following correctly gives the ratio of their conduction rates, (ΔtQ)2/(ΔtQ)1 ?
a) 21
b) 2
c) 2
d) 1