Aluminium Rod #1 Is 1

Aluminium rod #1 is 1.0 m long with cross-section area 2.0 cm². Aluminium rod #2 is 2.0 m long with cross-section area 4.0 cm². Aluminium rod #3 is 3.0 m long with cross-section area 9.0 cm². If each rod has the same temperature difference applied across its ends, which rod has the greatest rate of transfer of energy between its ends?

A) #1
B) #2
C) #3
D) #2 = #3, both greater than #1
E) They each have the same rate.