Which of the Following Statements Is True

Which of the following statements is true?

A) Interest rate parity indicates that the forward premium or discount should be greater than the differences in the national interest rates for securities of the same maturity.
B) Purchasing-power parity indicates that, in the long run, exchange rates adjust to reflect international differences in inflation so that the purchasing-power of each currency tends to remain the same.
C) The International Fisher Effect indicates that the nominal interest rate should be the same all over the world at all times if the market is efficient.
D) Both B and C)