Answer: Option (b) is correct.
Step-by-step explanation:
Correct option: Increases in the money supply lead to proportional increases in the price level but no change in real output.
According to the classical model, if there is an increase in the money supply then as a result it will increase the price level by the proportionate amount but there will be no change in the real output.
This means that if the money supply increases by 10% then as a result price level also increases by 10% and this change doesn't impact the real output.