If a force is applied in the same direction of an objects motion, the speed will: if a force is applied in the opposition direction of an objects motion, the speed will:

The action from a force  can  cause an  object  to move or  speed  up (accelerate),a force is applied in the same direction, the  object will speed  up or accelerate. if  an  object  is moving and there is an applied force in the  opposite  same  speed,  if  the  force is applied  perpendicular to the  direction  ofmotion.

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