Which of the following could be classified as a problem that could be answered with a technological design?

1) the need for clean water

2) the desire for faster computers

3) the desire for something that washes the dishes for you

4) all of the above

I think the answer is 4) All of the above!! :)

That would be kinetic energy

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