The spot rate between Japan and the U.S. is 148.35 = $1, while the 1-year forward rate is 148.03 = $1. A 1-year risk-free security in Japan is yielding 3.9%. What is the rate of return on a 1-year risk-free security in the U.S. assuming that interest rate parity exists? a. 4.12% b. 5.31% c. 4.46% d. 5.08%