A gold wire with dexameter 2.00 mm carries a current of 0.20 A. The number density of conduction elTo estimate the mean time τ between collisions for a conduction electron in the wire, assume that, between collisions, an electron moves with a constant acceleration a due to the electric field. Under this assumption, explain why the drift velocity should be vd ≈ 1 2 aτ . Then solve for the numerical value of τ

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