Which of the following is not a possible outcome of postulate C$-4,$ stability of the monetary unit?

If purchasing power of the monetary unit is not stable, some form of inflation accounting is appropriate.

If purchasing power of the monetary unit is not stable, historical cost is still justified.

If purchasing power of the monetary unit is stable, a system of current values is justified.

If purchasing power of the monetary unit is stable, retention of historical cost is justified.