Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be -

(a) 1:2

(b) 2:1

(c) 1:4

(d) 4:1

(a) 1:2

(b) 2:1

(c) 1:4

(d) 4:1