A2.4-m-high 200-m2 house is maintained at 22°c by an air-conditioning system whose cop is 3.2. it is estimated that the kitchen, bath, and other ventilating fans of the house discharge a houseful of conditioned air once every hour. if the average outdoor temperature is 32°c, the density of air is 1.20 kg/m3, and the unit cost of electricity is $0.1/kwh, the amount of money “vented out” by the fans in 10 hours is consider the specific heat to be 1.005 kj/kg·°c.

Ohm's law tells you that i = v/r where v is equivalent voltage and r is equivalent resistance of the circuit
since all circuits have the same voltage, your question is really asking which circuit has the lowest total resistance, since the lower the resistance, the higher the current
circuit a has a resistance of 5 ohms; circuit c is in series so has a resistance of 10 ohms; circuit b is in parallel and therefore has a resistance of 2.5 ohms (review your notes on adding resistances in parallel and series); therefore b has the highest current