A box has an applied force of 105 N [Right] and a force of friction of 65 N [left] as it
slides across a level floor. The mass of the box is 7.14 kg.
a) Calculate the force of gravity on the box. [1]
b) Draw and label a free-body diagram with all four forces acting on the box ( I
mentioned three but there is another). [2]

The answer is trial 3.

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