Which of the following is correct? a The short-run, but not the long-run, aggregate supply curve is consistent with the idea that a change in price does not affect real variables. b The long-run, but not the short-run, aggregate supply curve is consistent with the idea that a change in price does not affect real variables. c The long-run and short-run supply curves are both consistent with the idea that a change in price does affect real variables. d Neither the long-run nor the short-run aggregate supply curve is consistent with the idea that a change in price does affect real variables.