Why would Keynesian Economists agree with the Phillips Curve?

-Due to how they perceive the LRAS Curve. -Below Point A, where Output is Low and Unemployment is High, workers will Take on Jobs even if Wages are Low. Output will Rise and Inflation won't Increase at all -But between A and B, as you Increase Output and Lower Unemployment, Prices start to rise and rise. This is seen exactly from the Philipps Curve?