Which of the following best describes the real exchange rate?

	a.	The real exchange rate removes currency from the calculation and expresses the rate of exchange in terms of real goods
	b.	When APPP holds, the real exchange rate is 1
	c.	In addition to the nominal exchange rate (S), the real exchange rate depends on price levels in the countries
	d.	When RPPP holds, the real exchange rate does not change over time
	e.	All of the above
	f.	a and c