explain how learning is learning is achieve in the experiment conducted by lvan Pavlov about " Classic conditioning "

Which principle states: "geologic processes taking place on earth today operated similarly in the past and can be used to explain past geologic events"? a. lateral continuity

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