1. A soccer ball and a bowling ball have a head-on collision at this instant. Rolling friction is negligible.
2. | A weightlifter stands up at constant speed from a squatting position while holding a heavy barbell across his shoulders.
3. | A steel cable with mass is lifting a girder. The girder is speeding up:

26.4 is about the right time

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