Two metal rods 1 and 2 of same lengths have same temperature difference between their ends. Their thermal conductivities are K, and K, and cross sectional areas A and A, respectively. If the rate of heat conduction in rod 1 is four times that in rod 2, then (a) K,A = KA (c) K,A, = 2K,A, (b) K, A, = 4K,A (d) 4K,A = KA