Bowling balls are roughly the same size but come in a variety of weights. Given that the official radius a bowling ball should have is roughly 0.111 m 0.111 m , calculate the weight of the heaviest bowling ball that will float in a fluid of density 1.000 × 10 3 kg/m 3 1.000×103 kg/m3 .

The answer is 12, for the points

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