Equal temperature difference exists between the ends of two metallic rods 1 and 2 of equal length. Their thermal conductivities are K₁ and K₂ and cross sectional  areas are resepctively A₁ and A₂. The condition for equal rate of heat transfer will be

• A

  K₁A₂ = K₂A₁

• B

  K₁A₂² = K₂A₁²

• C

  K₁A₁ = K₂A₂

• D

  K₁A₁² = K₂A₂²