Answer: The correct answer is "c. real exchange rate is equal to one. A dollar buys as many goods in the U.S. as it does overseas.".
Explanation: The real exchange rate of one currency with respect to another is the purchasing power of a currency after its conversion.
That is, the real exchange rate is a measure that indicates the purchasing power of one currency against another. Unlike the nominal exchange rate, it takes into account prices in the country to which the currency belongs.