At a carnival, some students are riding bumper cars. A 100 kg bumper car gliding at 1.6 m/s bumps into a 120 kg bumper car
that is at rest. If they collide elastically and the 120 kg car has a velocity after collision of 1.45 m/s,
what is the final velocity of the 100 kg car after they bounce apart?

One splits the atoms and molecules  the other combines them

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