3.113 a heat pump is under consideration for heating a research station located on antarctica ice shelf. the interior of the station is to be kept at 15℃. determine the maximum theoretical rate of heating provided by a heat pump, inof power input in each of two cases: the role of the cold reservoir is played by (a) the atmosphere at −20℃, (b) ocean water at 5℃.

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

//(b) both involve the use of levers;