What is the relationship between Electric Field Strength and Charge? And when plotted, what would I have to do to get the slope to be a linear line?

50 meters per 5 seconds

No because a circle or pie graph usually shows percentages you'd need a line graph

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