Two basketballs of equal mass are rolling toward each other at constant velocities. The first basketball (B1) has a velocity of 4.3 m/s, and the second basketball (B2) has a velocity of -4.3 m/s.

If these basketballs have a perfectly elastic collision, B1 will have a final velocity of , and B2 will have a final velocity

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