Abody is falling from rest describes distances s1, s2, and s3 in the first, second and third seconds of its fall. then the ratio s1 : s2 : s3 is

The answer should be a.

Velocity is the speed of an object in a certain direction so you'd need to know speed and direction

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