How do we get the answer?

The inflation rate in the United States was 1.7% over the past one year, while the inflation rate in Brazil was 3.8\%. After supply and demand for the Brazilian real ( R$ ) have adjusted according to purchasing power parity, the exchange rate for the real as of today is $0.24. What was the spot exchange rate for the real one year ago? $0.235 $0.238 $0.242 $0:245 $0.248