A tall, open container is full of glycerine. At what depth h h below the surface of the glycerine is the pressure 2190 Pa 2190 Pa greater than atmospheric pressure? The density of glycerine is 1.26 × 10 3 kg/m 3 1.26×103 kg/m3 .

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

The answer to the question is (a)   

To find speed, or mph, use distance/time.