How might real business cycle theorists respond to evidence of procyclical inflation?

What will be an ideal response?

Since the aggregate demand curve is negatively-sloped, changes in potential output should relate negatively to inflation. Rising potential (actual) output should put downward pressure on prices, while negative productivity shocks should force prices up. Defenders of real business cycle theory may point to evidence that inflation is not consistently procyclical. Also, if aggregate demand shifts are correlated with changes in potential output, that might account for procyclical changes in inflation.