Are stairs a type of inclined plane?

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 disturbance in a transverse wave is perpendicular to the wave motion.unlike a transverse wave, the disturbance in a longitudinal wave is parallel to the wave motion (a), that is, back and forth.