The main ideas of Keynesian economics are:
a-the importance of the long run over the short run, and an emphasis on a vertical SRAS curve.
b-the importance of the long run over the short run, and an equal emphasis on the AD curve and the SRAS curve.
c-the importance of the short run over the long run, and an emphasis on the AD curve and a rising SRAS curve.
d-the importance of the free market with no government intervention, and an emphasis on monetary policy in the long run.