Some economists believe the economy is self$-$regulating. What does this mean?

It means the economy can remove itself from recessionary and inflationary gaps and produce at Natural Real GDP$.$

It means the economy is always in short$-$run equilibrium producing Natural Real GDP$.$

It means that inflationary gaps naturally change into recessionary gaps.

It means that recessionary gaps naturally change into inflationary gaps.

c and d$.$