10. If a car is moving down a straight highway at a constant speed of 70 miles per hour, it has no net force acting on it. The engine has to keep running to overcome the constant force of friction that is acting on the
car by the road.
a. true
b. false c. not enough information to determine

Answer(b) 60 miles per hour;

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