23. A Keynesian economist believes that(A) if the economy was left alone, it would rarely operate at full employment.(B) the economy is self-regulating and always at full employment.(C) the economy is self-regulating and will normally, though not always, operate at fullemployment if monetary policy is not erratic.(D) the economy is self-regulating and will normally, though not always, operate at fullemployment if fiscal policy is not erratic.